Pinus flexilis

PEST

 

   NAME

     Scale Insect

     Various Scale Species

 

   ORDER

     Hemiptera

 

Description of the Pest

Generally scales are soft bodied insects that have a hard (armoured) or soft covering to hide under. They have piercing and sucking mouth parts that are attached to the host, feed off sap and soft scales commonly producing sweet honeydew, which in turn attracts sooty mould and ants.

The adult female has a circular or oval covering depending on the species and is up to 8mm across. The first stage (crawlers) hatch and wander around the leaf surface until finding a suitable place to suck sap, normally in colonies and the smaller male is relatively inconspicuous.

 

Hard Scale                   Soft Scale, attending Ants

 

Cactus Scale (Diaspis echinocacti) has a circular greyish female and a narrow white male scale and is commonly found on house plants.

 

Chain Scales (Pulvinaria species) adult females are obvious with large group of eggs that are white or cottony-like, and the tiny young light green scales are flat and oval-shaped up to 2mm long. The legged nymphs are normally arranged from head to tail along the mid rib of the leaf, and may move to a new position to feed. They excrete honeydew and attract sooty mould and are found on Acacia and Acronychia species.

 

Chinese Wax Scale

 

Chinese Wax Scale (Ceroplastes sinensis) is a domed wax scale that has dark spots around its margin and immature scales form waxy material around there margins.

 

Fern Scale on Aspidistra elatior

 

Fern Scale or Coconut Scale (Pinnaspis aspidistrae) appears as flecks up to 0.15mm long with a white covering over the male congregating on the underside of the fronds on the axils and among the sporangia causing them to turn yellow. Many species of fern are susceptible to infestation.

 

                  Flat Brown Scale

 

Flat Brown Scale (Eucalymnatus tessellates) are light brown up to 0.5mm long, flat and closely attached both sides of the leaf and causing yellowing of the foliage.

 

Juniper Scale (Diaspis carueli) is tiny and circular, white maturing to grey-black and as it feeds the needles turn yellow and die.

 

Oleander Scale (Aspidiotus hederae) is a pale yellow circular scale up to 3mm across and is found in dense colonies on the stem or leaves.

 

Tea-tree Scale (Eriococcus orariensis) are a creamy blue colour normally packed along the branches and are plump and rounded to 4mm across.

 

                  Wattle Tick Scale

 

Tick or Wattle Scale (Cryptes baccatus) adult is domed, blue-slate colour with a leathery covering up to 10mm long. All stages of growth are found in groups of over forty, packed along the stems and normally tended by ants as they produce large amounts of honeydew. A serious pest of Acacia species found inland or coastal from temperate to sub tropical climates and commonly accompanied by Sooty Mould.

 

Toxic Scale (Hemiberlesia lataniae) is a tiny flat rounded scale up to 0.15mm long and is white to pale pink. It is normally found in colonies on the small branches and twigs of shrubs. It injects a toxic substance into the host as it sucks sap causing the death of the branch.

 

Wattle Scale (Pseudococcus albizziae) is soft, plump and secrets cotton-like threads. It is not a true scale insect and is simular to mealy bugs. It is reddish-brown up to 0.4mm long and secrets large amounts of honeydew as it sucks sap in colonies along the branches.

 

Life Cycle

These insects have a Hemimetabolous life cycle, ie. When the immature nymphs resemble the adults.

 

Appearance of the Pest

All parts of the plant above the soil may be attacked, but normally the stems and leaves and scale tends to favour well-lit positions.

 

Period of Activity

The nymphs and females are active for most of the year, in warm climates. Once they selected a position they attach and don't move. Normally the winged or wingless males are mobile and only soft scales produce honeydew.

 

Susceptible Plants

There is a wide range of susceptible plants including citrus, willows, holly, and many ornamentals, such as roses or Paeonia species. It also attacks indoor or glasshouse plants and Australian native plants such as wattles, hakeas, grevilleas and eucalyptus.

 

Acacia species are attacked by the Tick or Wattle Scale, which infest twigs and small branches and heavy infestations will kill the host plant.

 

Acer species are attacked by the Cotton Maple Scale (Pulvinaria innumerabilia) which prefers Acer saccharinum. Nymphs first attack the leaves and the brown adult scale is covered in a woolly mass up to 14mm across, normally found on the underside of the stems and twigs.

 

Acmena smithii, Melaleuca, Syzygium and Pittosporum species are attacked by the Chinese Wax Scale.

 

Aesculus species are attacked by several scale insects including the Walnut Scale (Aspidiotus juglans-regiae) which is saucer-shaped and attacks the main trunks.

 

Agave species are susceptible to several types of scale including (Aspidiotus nerii), (Aonidiella aurantii) and (Pinnaspis strachani), but generally do not require control.

 

Asplenium australasicum

 

Asplenium australasicum is susceptible to Coconut Scale or Fern Scale (Pinnaspis aspidistrae). It is normally found on the under side of the fronds. Small infestations cause little damage.

 

Bougainvillea species may be attacked by the soft scale (Coccus hesperidum) outdoors or under glass.

 

Calluna and Vaccinium species are attacked by the Oyster Shell Scale (Lepidosaphes ulmi).

 

Camellia species may be attacked by the Florida Red Scale (Chrysomphalus aonidum), which is small, circular and black and is found firmly attached to the underside of the leaf along the veins. On inspection after removing the scale the insect has a pale yellow body. Camellias are also attacked by a large variety of scale insects including Tea Scale and Camellia Scale.

 

Carpinus species may be attacked by the scale (Phenacoccus acericola). It is found on the underside of the leaves forming a white cotton-like clump along the veins.

 

Casuarina and Allocasuarina species may be attacked by the Casuarina Scale (Frenchia casuarinae), a black hard scale that is upright to 4mm with a pinkish body. During attachment the surrounding tissue swells up and in time can, form galls. This weakens the wood and in severe infestations may kill the tree.

 

Cotoneaster species are attacked by up to four species of scale including the Oyster Shell Scale (Lepidosaphes ulmi).

 

Cupressus species are attacked by Bark Scale (Ehrhornia cupressi) is pink and covered in white wax. Heavy infestations cause the leaves to turn yellow or reddish.

 

Flat Brown Scale on Cycas revoluta

 

Cycads, palms and some species of Callistemon are attacked by the Flat Brown Scale.

 

Erica species are attacked by several species of scale including, Greedy, Oleander and Oystershell scale.

 

Jasminum species can be infested with up to twelve types of scale.

 

Juniperus x media and other conifer species are attacked by the Juniper Scale.

 

Leptospermum species are attacked by the Tea-tree Scale which produces ample honey dew that promotes sooty mould.

 

Palm and Fern species are susceptible to attack by the Coconut Scale or Fern Scale (Pinnaspis aspidistrae) which infests the underside of the leaves. They are also hosts for many other scale species such as red, cottony cushion and tea scale.

 

Pinus species are attacked by several species of scale including the Pine Tortoise Scale (Toumeyella numismaticum) and the Red Pine Scale (Matsucoccus resinosae).

 

Polygonum odoratum is attacked by a small brown scale.

 

 

Sorbus aucuparia is attacked by a five species of scale insect, including Black Cottony Maple, San Jose and Scurfy. Generally they suck on the sap of the new growth and leaves.

 

Strelitzia species are attacked by the Greedy Scale (Aspidiotus camelliae).

 

Damage Caused

Leaves become yellow and are shed prematurely and there may be twig or stem die-back. When the infestation occurs on fruit, the fruit is small and its skin becomes pitted and cracked. Small trees and saplings that are heavily infested may be seriously damaged or die. Sooty mould can cover fruit or leaves causing a secondary problem.

 

Cactus Scale can completely cover the host cactus sucking sap and causing it to die.

 

Cultural Control

Dead or damaged parts of the plant should be removed and destroyed including fallen fruit. Small infestations may be removed by hand or squashed on the stems. Healthy plants are less susceptible to attack, so maintain vigour of the plant and avoid using high-nitrogen fertiliser that produces excessive soft young growth.

When pruning susceptible plants paint the cuts with antifungal sealant paint as scale insects are attracted to the sweet smell of the sap. This will reduce the infection rate of the plant.

 

Biological Control

Natural predators such as parasitic wasps may reduce numbers of active nymphs; parasitic wasps are bred commercially in some areas for this purpose. It should be noted, however, that wasps would avoid dusty conditions.

Other predators that assist in control are assassin bugs, ladybirds, lacewings, hover flies and scale eating caterpillars. A variety of birds also attack scales.

The control of ants that transport aphid from one host to another also reduces infestation and can be carried out by applying at least three greased bandages 5mm apart around the stem or trunk of the plant.

 

Chemical Control

Spray the entire plant with dilute white oil solution; a follow-up spray may be required after four weeks, for heavy infestations. Spraying of chemicals will also kill of natural predators and in some cases the secondary scale infestation is more prolific especially when using copper based chemicals.

Some chemical controls, such as methidathion, are available - please seek advice from your local nursery as to the suitable product for your area.

Note

Always read the label for registration details and direction of use prior to application of any chemicals.

PEST

 

   NAME

     Borer (General)

     Various Borer Species

 

   ORDER

     Various

 

   FAMILY

     Various

 

Description of the Pest

Generally the larvae bore holes into the heartwood, sapwood or down the centre of twigs. These tunnels may be small or large, deep or shallow and when they emerge from their tunnels at night, they feed on the surrounding tissue. Entrance holes may be covered by a layer of chewed wood fragments ("frass"), silk webbing or exposed and the tunnels may be solitary or form galleries. Certain species attack only twigs and young shoots, while others attack the trunk or roots.

 

Fruit tree moth borer damage

 

The adults female of a fruit tree moth borer normally deposits eggs in damaged areas of the bark or where there is and existing active site. The larvae vary but generally they are creamy to brown, thick soft grub-like reddish brown, and up to 40mm in length.

The adults are white, satiny moths with 40-60mm wingspans with their black abdomens fringed with orange-brown hair or beetle lava that has been deposited in the bark or twigs then tunnels the host.

 

American Plum Borer (Euzophera semifuneralis) lava is pinkish white to brownish green and attacks the inner bark and cambium region of the tree causing premature death. It is normally found on Platanus orFraxinus species and may also infest many species of fruit trees.

 

Apple Root Borer (Leptopius squalidus) female adult is a weevil to 20mm long and feeds on the leaves and the plump, legless grub-like lava feeds on the roots of the same host forming tunnels in the deep roots. It is commonly found on Acacia and Eucalyptus species damaging the anchorage of the plant.

 

Banksia Borer (Cyria imperialis) adult is a black beetle with yellow markings on its wing covers growing to 15mm long. The thickish legless lava is white, tapering from the head and forms flattened tunnels into the heartwood of the host.

 

Bronze Birch Borer (Agrilus anxius) is a bronze coloured beetle up to 14mm long and lays eggs in crevices in the bark. The legless white larva grows to 20mm long and feeds on the sapwood girdling the branch with flat irregular galleries.

 

Cedar Tree Borer (Semanotus ligneus) is a black beetle with orange and red markings on its wing covers and grows to 12mm long. The larva feeds on the sapwood of Sequoia, Thuja species and Pinus radiata with curved tunnels that may girdle branches.

 

Chestnut Borer (Agrilus bilineatus) adult is a tiny slender, blackish green beetle up to 8mm long emerging during spring. The small white larvae have a flat head and are up to 15mm long, forming galleries under the bark of Quercus species.

 

Cypress Bark Beetle (Phloeosinus cupressi) adult is dark brown with a blackish head, oblong in shape up to 3mm long. The tiny beetles tunnels under the bark of the host and deposits eggs. After hatching the tiny 4mm long, legless larvae bore into the heartwood damaging the tree. After they pupate in the tunnel they emerge through small round holes, commonly many together on the trunk. Damaged trees show signs of browning and dead leaves in the upper branches or falling damage twigs. Cupressus species are particularly vulnerable to attack.

 

Deodar Weevil (Pissodes nemorensis) is brownish with an obvious snout feeding on the cambium layer and deposits eggs in the bark of the leader and branches. The white lava tunnel the wood eventually killing the leader.

 

European Corn Borer (Pyrausta nubilalis) is a small moth that lays up to twenty eggs on flower buds. The young flesh coloured larvae mature to a reddish brown and each of its segment has four, spined dark spots.

 

Elephant Weevil (Orthorhinus cylindrirostris) is a grey or black insect up to 20mm long and lays eggs in the bark near the base of stressed trees. The larva tunnels its way through roots or trunks depositing frass as it goes, then emerging from a second round hole. The adults eat strips from the leaves, normally not bothering the plant.

 

Elm Borer (Saperda tridentate) adult is a greyish beetle with red bands and black spots on its wing covers and is up to 12mm long. The eggs are laid on the bark and the whitish lava tunnels into the bark and sapwood where it overwinters. It is normally found on Ulmus species.

 

Iris Borer (Macronoctua onusta) is born from a grey moth with a wing span up to 30mm across, and lays eggs that overwinter in old leaves and debris. As the leaves emerge the eggs hatch entering the leaves at the base, visually forming tunnels and growing to 30mm long. In the later season flower buds may be attacked. Both flowers and leaves eventually turn brown and die.

 

Lilac Borer (Podosesia syringae) adult is a wasp-like moth that produces pure white lava with a brown head that are up to 25mm long. It initially feeds in the sapwood causing wilting before tunnelling the hardwood making the branches brittle. Evidence of frass is found at the tunnel entrance and secondary fungal attacks infect the holes. Normally found on Syringa species.

 

Locust Borer (megacyllene robiniae) adult is a black beetle with golden spots, up to 20mm long and produces a small larva that tunnels galleries into the sapwood causing a blackish discolouration. Robinia species are normally attacked.

 

Mottled Borer (Cryptorhynchus lapathi) attacks Salix species. The adult beetle is black up to 10mm long and the lava bore into the surface of the stem causing swollen growth. Salix species are attacked.

 

Murry Pine Borer can be two species (Diaoxus erythrurus) and (Diaoxus scalaris). The adults are glossy green-brown beetles that are up to 20mm long and the white grub-like lava is legless, tapering from the head. They tunnel into the sap or hardwood of the trees forming connecting galleries causing ringbarking and creating brittle branches, commonly fond on Callitris species.

 

Peach Borer (Sanninoidea exitiosa) is a larva that tunnels roots causing gummosis that is mixed with frass at the crown just below soil level. The affected Prunus species produce yellowish leaves and grows poorly. There is another borer, Lesser Peach Borer (Synanthedon pictipes) which attacks any part of the plant from the trunk to the branches and is found on several Prunus species.

 

Puriri Moth (Aenetus Virescens) a New Zealand short lived moth that grows with a wing span of over 100mm (4in) wide laying eggs on the forest floor at night during spring. The caterpillars grow  to 100mm long feeding on leaves and  then ascending into the trees and entering the cambium layer up to 150mm deep forming a characteristic '7'-shape burrow that is concealed by frass. The caterpillar may live for 7-years before pupating and collectively they ring bark branches or trunks causing dieback.

Many New Zealand plants including Nothofagus solandri, Pomaderris spp.and ornamentals such as Quercus spp. Betula pendula, Salix spp. Populus spp. Acer spp. Citrus limon and Paulownia spp. are attacked. Control is difficult and generally the plants tolerate attack.

 

White Pine Weevil (Pissodes strobi) lava feed on the inner bark and sap wood of terminal shoots causing ringbarking and death of the shoot. The reddish brown beetle up to 6mm long is mottled in white and emerges during early summer then lays yellowish lava that are up to 9mm long.

 

Scribble Moth (Ogmorgraptis scribula) is a grey moth up to 0.4mm wide and produces a cream to brown larvae that is also about 0.4mm long and tunnels in the bark causing a scribble effect. This normally has no detrimental effect on the tree.

 

Spotted Hemlock Borer (Melanophila fulvoguttata) adult is a colourful metallic beetle with yellowish red spots on the wing covers and lays eggs in cracks in the bark. The white lava is up to 14mm long and forms galleries in the bark and sapwood of the host.

 

The large Swift Moth and Wood Moths can have a wing span up to 250mm wide and produce large larva that are grub like up to 150mm long, some with horny plates on the thorax. These larvae bore tunnels that are up to 30mm across straight through the heartwood of the host plant. The larvae may live in the tunnel for up to five years before pupating.

 

Red Cedar Bark Beetle (Phloesinus dentatus) is a small beetle up to 3mm long and lays its larva in excavations in the bark. When the larva emerges they bore galleries in the bark and tend to be more prevalent in stressed or recently transplanted plants.

 

Vegetable Weevil (Listroderes difficilis) is found during cooler weather (spring or autumn). The adult brown beetle up to 19mm long with a "V" mark on its back and the eggs are laid in the soil around the base of the host plant. The cream coloured lava emerges in spring after rain and feed on the lower leaves forming irregular holes or chewing holes in stems. The lava also feed on fleshy roots boring holes into carrots. Both the adults and lava cause damage, feeding on the plant during the night and resting at the base or under ground during the day. The lava pupates in the soil over winter.

 

Wattle Web-covering Borer (Cryptophasa rubescens) adult is a satin coloured moth that is up to 50mm across and deposits green fleshy lava that is up to 35mm long. The lava forms shallow tunnels in the bark and sap wood of the host and camouflages it with chewed wood and faeces that is webbed together. Commonly seen attacking the branches on Acacia species.

 

Life Cycle

These insects have normally have a Holometabolous life cycle. But some borers such as Termites have a Hemimetabolous life cycle.

Eggs are laid singly or in groups, in damaged areas of the bark and branch. Larvae shelter in tunnels they create in the wood and some species may take many years to pupate and emerge as an adult. This may take place in live or dead wood.  Other species such as Corn Borer can have up to two generations per year.

 

Termites and their damage

 

Distribution of the Pest

Borers are found throughout the world with many species found in Australia both on the coast and inland.

 

Period of Activity

Varies with the insect concern. Many larvae can be active for many months. Termites are active all year.

 

Damage Caused

Most damage appears on branches or trunks where the larvae feed on the soft tissue and extensive feeding may cause ring-barking. Normally plants survive borer attack but repetitive attack will cause the death. Certain species are a serious pest in plantations or monocultures such as the Pine Bark Weevil, and the Sirex wood wasp.

 

Typical borer damage by a moth larva

 

Chestnut Borer feeds on the sap wood ringbarking large branches and overwinters in the tunnels.

 

Corn Borer feeds on flower buds and leaves resulting in there death, after which the larva tunnel down the stem causing wilting. There are many crop plants and ornamentals that are affected by this larva.

 

Swift Moth and Wood Moths weaken trees by boring large tunnels through the branches that may not be noticed until holes are cut through the bark during emergence.

 

Iris Borer damages leaves to turn brown and wilt, flowers also turn brown and with the aid of a bacterial rot, collapse and die. This damage may be extended to the flower stalk.  

 

Stem Borer (Papaipema nebris) is a small lava to 12mm long, and attacks many garden plants including Lilium, Aster, Alcea and Phlox species

 

Borer Damage          Resin oozing from a trunk

 

Susceptible Plants

There are many plants that are attacked by these pests including Banksia, Callistemon, Melaleuca, Lagerstroemia, Jacaranda species, and flowering stonefruit. Eucalyptus, Acacia species and many ornamental such as Acer species. Plants that are stressed, are particularly venerable.

 

Acacia and Eucalyptus species are attacked by Swift Moths and Wood Moths.

 

Acacia species are susceptible to attack from the Wattle Web-covering Borer (Cryptophasa rubescens), which weakens and causes die back of branches.

 

Acer platanoides is attacked by the Leaf Stalk Borer (Nepticula albostriella) that tunnels into the petiole of the leaf turning it blackish and also attacks the fruit.

 

Acer saccharinum is attacked by the Petiole Borer (Caulocampus acericaulis) which tunnels in the petioles. It generally attacks the leaves on the lower branches causing them to fall.

 

Acer species may also be attacked by several borers including the Flat Headed Borer (Chrysobothris femorata), a 25mm long lava of a coppered coloured beetle, that tunnels galleries under the bark girdling the trees The Sugar Maple Borer (Glycobius speciosus) which girdles branches killing them and the Leopard Moth (Zeuzera pyrina) lava that tunnels large holes into branches making them structurally weak. This lava can grow to 80mm long and 12mm thick overwintering in the tunnels.

 

Banksia species are attacked by the Banksia Web-covering Borer (Xylorycta strigata) a greenish lava up to 40mm long that tunnels down the centre of branch tips. The entrance is covered in silken web littered with faecal material and causes the death of the branchlets.

 

Betula and Populus species are attacked with the Bronze Birch Borer (Agrilus anxius) and heavy infestation may kill the tree. Populus species are also attacked by the Poplar Borer (Saperda calcarate).

 

Brachychiton species are attacked by the Kurrajong Weevil (Axionicus insignis) the lava of this plump greyish weevil is white and legless, entering the plant through wounds forming rounded tunnels that may girdle the tree, killing it.

 

Carya species are attacked by the Painted Hickory Borer (Megacyllene caryae). The adult dark brown beetle has obvious zig zag lines on its wing covers and the lava is cream coloured, both up to 20mm long. The lava tunnels the sapwood of living trees causing ring barking and also tunnels dead trees.

 

Cornus species are attacked by several borers such as the Flat Headed Borer (Chrysobothris femorata) and the Dogwood Borer (Thamnosphecia scitula).

 

Cupressus species are attacked by the Cypress Bark Beetle (Phloeosinus cupressi) causing the branches to turn brown and die off from the top or causing the leaves to wilt. On first indication of infestation selective prune off damaged areas or remove the tree.

 

Hakea sericea and other Hakea species are attacked by the Web-covering Borer (Neodrepta luteotactella). The larvae bore into the twigs and fruit forming a small covering of frass. This insect also infects Macadamia species. Hakeas are also attacked by several other web-covering borers.

 

Hakea sericea

 

Pinus and Picea species are attacked by the White Pine Weevil (Pissodes strobi) in the northern hemisphere.

 

Samanea saman is attacked by the borer (Xystrocera globosa) which chews into the sap wood of stressed trees and can cause serious damage.

 

Sorbus aucuparia is attacked by the Round Headed Borer (Saperda candida) which forms galleries in the trunk at ground level, forming round holes in the bark.

 

Tilia species are attacked by the European Bark Borer (Chrysoclista linneela), which feeds on the bark and thew Linden Borer (Saperda vestita) that attacks the base of the trunk or roots.

 

Tsuga species are attacked by Spotted Hemlock Borer (Melanophila fulvoguttata).

 

Vaccinium ovatum is infested by the Azalea Stem Borer (Oberea myops). The yellowish lava of this beetle bores into the tips of stems during the flowering period and is up to 12mm (½in) long. It is also commonly found on Rhododenron species.

 

Control

 

Cultural Control

Larvae may be destroyed after exposure by pulling away the covering pad of frass, or by pushing a length of wire into the tunnel. Damaged branches may be removed. Improve the culture by feeding and watering the plant.

 

Frass due to the Fruit tree moth borer

 

Biological Control

No effective biological control though certain species of trees exude gum or resin sealing the holes and limiting the activity of the larvae or causing its death.

 

Chemical Control

There is no satisfactory chemical control most borers of live wood.

Note

It is your responsibility by law to read & follow the directions on the label of any pesticide

PEST

   NAME

     Caterpillars (General)

     Various species

Description of the Pest

There are many types of caterpillars from moths or butterflies, cutworms, bag moths, case moths, leaf rollers leaf skeletonises. The larvae generally eat leaves, seeds, flowers or buds by chewing out pieces. The size of the piece will depend on the size of the caterpillar and generally they are voracious eaters. The method of eating varies such as the leaf skeletoniser which leaves a network of veins or whole leaves are consumed.

The larvae have mainly 4 or 5 pairs of prolegs except Loopers which have 2 -3 pairs of prolegs. The number of prolegs can help in identifying the insect.

Small and Large Types     

Casuarina Moth (Pernattia exposita) is gregarious, brown with a large head and tufts of hairs that line the slender body. It grows to 25 mm long and forms a tightly woven cocoon on the side of branchlets. The large female adult moth has a stocky body and generally slow moving, the male is smaller.

The larvae cause extensive damage to A. littoralis, A. stricta, C. cunninghamiana, C. glauca, and C. equisetifolia.

The hairy larva feed on the 'leaves" phyllodes, and stems, this can lead to ringbarking and death of branches.

Monitoring

Place sheets on the ground and disturb (shake) the tree for the larva drop to the ground on silken threads.

Spruce Budworm (Choristoneura fumiferana) is a reddish brown with a yellow stripe on its side and chews on the opening buds and the needles of the host. The adult moth is dull grey with brown bands and spots on the wings, appearing in early summer.  The larva is very destructive in northern hemisphere coniferous forests.

Banksia Moth (Danima banksiae) is a caterpillar up to 60 mm long and is brown with black and white markings on its sides and when disturbed it arch backwards and reveal an extruded red underside, close to its head. The grey adult moth has an orange coloured body with a wing span that is up to 80mm across with black and white markings.

Banana moth (Opogona sacchari) is in the order Lepidoptera. This nocturnal moth as a wing span up to 25 mm wide and is bright yellowish brown with a dark brown spot on the wings.  It has a life cycle that lasts approximately 3 months with the eggs hatching in 12 days and the whitish larva with a reddish brown head is up to, 26 mm long, and lives for 50 days at 15° C. In warmer climates life cycle is quicker with up to eight generations per season. The female moth uses a ovipositor to lay up to 500 eggs in groups of five amongst the crevices of the plant. The voracious larvae tunnel into the plant, avoiding light.  In bananas it infests developing fruit and in ornamental plants it prefers the fleshy stems, particularly in cacti, begonias, African violets and is also a serious pest of Pritchardia and Chamaedorea species. Symptoms include tunnelling activity, which may be difficult to see then dead areas appear on the stems. As the caterpillars destroyed xylem tubes leaves begin to wilt and the plant may collapse and die. In European countries it is a glasshouse pest that is controlled chemically.

Pritchardi species      Banana moth larvae

European Pine Shoot Moth (Rhyacionia buoliana) lays eggs on Pinus species during late spring on the new buds and the emerging caterpillars in late summer feed on the shoots causing them to fold and become deformed, eventually dieing.  A major problem in the pine forests of the northern hemisphere

Large Grass Yellow Butterfly (Eurema hecabe) is a small attractive yellow butterfly. with a wing span of 40 mm that lays its eggs on the feathery leaves on Acacia species such as A. baileyana, (Cootamundra wattle), A. spectabilis (glory wattle). Other plant foods include Cassia spp, Caesalpinia spp, Senna spp. Albizia julibrissin (silk tree) A. paraserianthes (Albizia) sp Aeschynomene sp (Budda pea), Indigofera australis (Australian indigo's), Sesbania cannabina (yellow pea-bush), Senna surattensis (Glossy shower), Leucaena leucocephala (wild tamarind).

The small lava are up to 15mm long, green with white lateral bands and feed on the leaves at night in small groups, hiding under the leaves during the day. Large infestations may strip trees and require control. The larva of this insect does not feed on grasses. The adults are important pollinators of many Australian native plants. Various sub species of this insect are found through out Asia.

Gypsy Moth (Porthetria dispar) lava is a hairy grey caterpillar that is marked with blue and red dots along its back and can grow to 75mm long. It is capable of defoliating large trees and is a major problem for several species. A major problem in the northern hemisphere.

Lawn Armyworm

Lawn Armyworm (Spodoptera mauritia) is a plump, smooth caterpillar that is darkish brown to black with multiple stripes and pattens along its body. It can grow to 50mm long and tapers from the head. They are gregarious and move around in groups, like an army. If disturbed the larva drop to the ground and curl up, "faking death"  The larva pupate in the soil. They are a pest of grasses and monocotyledon crops mainly.

This insect is also found throughout Asia.

Monitoring

Drench a known area with old fashion soap 2L / 1000 cm 2. Note the numbers of larvae emerging.

Oblique-banded Leaf Roller (Choristoneura roseceana) lava feeds on the leaves and forms a nest by drawing the leaf margins together using silk threads. The adult moth is up to 25mm across the wingspan and is reddish brown with three darker brown bands across the wings. This is a problem in the apple growing areas of North America. It feeds on Maples, hawthorns, crab apples, Blackberry (bramble) and raspberries.

Red Humped Caterpillar (Schizura concinna) is a lava has a red head and humps with yellow and black strips on the body. It grows from eggs that were laid on the underside of leaves by the adult greyish brown moth that has a wing span up to 30mm across.

Tailed Emperor Caterpillar (Polyura pyrrhus spp. sempronius) adult is a large butterfly with a wing span up to 110 mm with four long tapering tails and the rear of the wings. The fleshy caterpillar with four obvious backward facing horns on a shield shape head. It is dark green with yellowish bands and transversal stripes over its back and grows up to 80 mm in length.

It is commonly found solitary or in small groups. Found over much on mainland Australia. The adults are attracted to overripe fruits they become drunk on this and so are easy to capture. The larvae feed on many plants including, Acacia baileyana (Cootamundra Wattle, A. spectabilis (Glory wattle), Delonix regia (Poinciana), Cinnamomum camphora (Camphor laurel) Robinia pseudoacacia (Black or false locust) Lagerstroemia indica (Crepe Myrtle), Argyrodendron actinophyllum (Black booyong), Celtis spp (Hackberry), Brachychiton spp (Kurrajongs) Gleditsia triacanthos (Honey locust).

Verbena Moth (Crambodes talidiformis) lays its eggs on the outside of the plant and the small green caterpillar that attacks seed pods by entering and eating the contents. It half emerges while pupating appearing as a small brown bump circled by a black ring. Native to North America

White Tussock Moth (Hemerocampa leucostigma) produces lava that is up to 50mm long. It has a red head with a yellow body that is marked in black and has four tufts of hair. The caterpillars pupate on the branches and the eggs laid by the adult moth overwinter on the trunk and are covered in a white waxy material. They are found on Aesculus species. A pest in North America of Oaks.

Life Cycle

This insect has a Holometabolous life cycle, i.e. it has a larval and a pupal stage.

Distribution of the Pest

Many species are found throughout the world from tropical to temperate regions and most of the adults are capable of by flying

Many hairy caterpillars can be irritating      Leaf Skeletonised

Period of Activity

Most active during the warmer months from spring to autumn.

.

Damage Caused

Leaf Rollers

Caterpillar Inside a Tomato

Susceptible Plants

A wide range of native and exotic plants are attacked and can be a major problem in commercial crops or turf grasses. Plants with soft-textured foliage (eg vegetables, some indoor plants) are preferred, but trees and shrubs are commonly attacked.

Malvaceae Abutilon spp, Hibiscus spp and other members of the family are attacked by the castor oil looper, Croton caterpillar (Achaea janata) which feed on leaves. The tip borer Cotton tipworm (Crocidosema plebejana), Rough bollworm (Earias huegeliana) which feeds on young stems, flowers and seeds. A leaf miner (Phyllonorycter spp)

Acer saccharinum and Fagus species are attacked in North America by the Maple Leafcutter (Paraclemensia acerifoliella) that forms a small cocoon in leaves that it skeletonises.

In Australia Case moths and Painted apple moths (Teia anartoides)

Ailanthus altissima is attacked by the Cynthia Moth (Samia cynthia) light green lava, which eats leaves and the Ailanthus Webworm (Atteva aurea) which are olive-brown caterpillars that form web nests in the leaves.

Antirrhinum species are attacked by the Leaf Tier (Udea rubigalis) lava. This caterpillar eats pieces out of leaves and binds them together forming a nest. It is more commonly found in glasshouse culture.

Berberis species may become infested with the Barberry Worm (Omphalocera dentosa). This small caterpillar is black with white spots, up to 14mm long and feeds on young shoots and leaves. It also binds the shoots with a silken thread to form a nest.

Betula species are attacked by the Leaf Skeletonizer (Bucculatrix canadensiella). The small adult moth has brown wings with a whitish underside and its yellow green, 7mm long lava skeletonise the undersides of the leaf turning it brown.

Brachychiton, Senna and feathery-leaved Acacia species are attacked by the Tailed Emperor Caterpillar, particularly in dryer periods.

Catalpa species are attacked Catalpa Sphinx (Ceratomia catalpae). This large yellow and black Caterpillar grows to 76mm long and attacks the leaves.  Large infestations can completely stripped a tree and control is carried out by spraying.

Calendula and Canna species are attacked by the Woollybear Caterpillar (Diacrisia virginica) which has yellow and black lines down its body is up to 50mm long and eats the leaves or flower buds. In Canna species the chewed holes tend to be in a straight line across the leaf.

Celtis species are attacked by the Spiny Caterpillar (Nymphalis antiopa) which is reddish, up to 50mm long and feeds on the leaves at the top of branched in groups.

Cheiranthus species are attacked by the Diamond-backed Moth (Plutella maculipennis) lava, which is a small green caterpillar to 14mm long that feeds on the underside of leaves and may form a shot hole appearance. It forms a small cocoon to pupate in and in cooler climates it may be found in glasshouses.

Cotinus, Fraxinus, Betula, Cornus, Crataegus, Aesculus, Tilia, Acer, Quercus and Populus species are susceptible to attacked by the Oblique-banded Leaf Roller (Archips rosaceana)

Iris and Antirrhinum species are attacked by Verbena Moth.

Picea, Abies, Tsuga and Pinus species are attacked by Budworm commonly found in the northern hemisphere.

Populus and Carya species are attacked by the Red Humped Caterpillar which chews the leaves.

Quercus species are attacked by several caterpillars including Saddleback Caterpillar (Sibine stimulea) and Datana Caterpillar (Datana ministra) that feed on the leaves.

Samanea saman is attacked by several caterpillars (Ascalapha odorata, Polydesma indomita and Melipotis indomita). These caterpillars defoliate the tree but cause no long term problems.

Spiraea, Fraxinus, Betula, Cornus, Crateagus, Acer, Quercus and Populus species are attacked by the Oblique-banded Leaf Roller.

Ulmus, Salix, Crateagus, Tilia, Quercus and Populus species, Pseudotsuga menziesii are attacked by the Gypsy Moth (Porthetria dispar).

Ulmus species are attacked by the Spring Cankerworm (Paleacrita vernata), which chews the leaves during spring and the Fall Cankerworm (Alosphila pometaria), which also eats the leaves during autumn. Ulmus  species are also attacked by several caterpillars including the lava of the Leopard Moth (Zeuzera pyrina) and the Tussock Moth (Hemerocampa leucostigma).

Cultural Control

Small numbers may be removed by hand and squashed while others species such as the Casuarina Caterpillar drop to the ground when disturbed by hitting with a stick or shaking the plant. On the ground they can be squashed or collected and placed in a bucket of soapy water.  All rubbish around plants and glasshouses should be cleared as certain moths overwinter in such places.

Biological Control

There are many natural predators that reduce numbers including birds, lizards, frogs; other predators are wasps, viruses, and fungi.

Chemical Control

The small plant may be sprayed using Pyrethrum-based insecticide to reduce numbers or dusted with an equally environmental friendly chemical. In severe cases crops may be sprayed with Carbaryl.

Note

Always read the label for registration details and direction of use prior to application of any chemicals.

PEST

   NAME

     Sawfly (General)

     Various Sawfly Species

   ORDER

     Hymenoptera

Description of the Pest

Adult sawflies are wasps that have derived the name Sawfly from the sawing action to open leaves using there ovipositor. The adults are usually colourful insects. The fleshy larvae normally are tapering caterpillars, some with pointed spine on the tale and are many different colours from black-blue to brown and orange.

These insects have a Holometabolous life cycle, ie. When metamorphosis is observed during the pupal stage.

                 

They are commonly called "spitfires" because, when disturbed, they bend back their bodies and exude a strong, eucalyptus-scented liquid from their mouths. This exudate contains concentrated eucalyptus oil, which can cause severe eye irritation. The non-feeding adults are seldom seen. Sawflies have a complete metamorphosis, pupating in cocoons in the soil for months or years.

Eucalyptus Sawfly (Perga kirbyi) lava is pale brown up to 40mm long. It is a plump grub with a black head and a yellow tipped tail and can be found in groups during the day, but spreads out at night to feed. When disturbed they react by arching there head and wiggling there tail.

European Spruce Sawfly (Diprion hercyniae) feeds on the old growth causing stunting of the host and the larvae overwinter in cocoons on the ground.

Ironbark Sawfly (Lophyrotoma interrupta) is a fleshy tapering grub up to 40mm long. It is pale brown with a black head and a yellow tip on its tail.

Long-tailed Sawfly (Pterygophorus insignis) larvae are greenish with a textured surface and a long pointed tail.

Pin Oak Sawfly (Caliroa lineata) adult is shiny-black up to 6mm long with four wings and the greenish larvae is up to 14mm long. It feeds by skeletonizing the underside of leaves turning them golden-brown as they die and an infestation in a large Quercus species is easily recognisable.

Pine Sawfly (Zenarge turneri) lays larvae that are rough and fleshy up to 10mm long with the abdomen curled.

Steelblue Sawfly

The adult Steelblue Sawfly (Perga dorsalis) female is steel blue in colour, with yellow antennae and legs, growing up to 20mm long, with 40mm wingspans. The insect is called a "sawfly" because of the sawing action of the ovipositor. The yellowish-brown larvae have chewing mouth parts.

Appearance of the Pest

During the day, sawflies congregate in clusters, separating at night to travel and feed on the foliage of the host plant.

Period of Activity

Caterpillars appear in spring through summer and are found from tropical to sub-tropical and temperate regions.

Susceptible Plants

There are many ornamental and Australian native plants that are attacked including Eucalyptus camaldulensis, E. blakelyi, E. melliodora, and E. pauciflora and Callistemon, Leptospermum species.

Eucalyptus species are attacked by the Eucalyptus Sawfly (Perga kirbyi) which can defoliate a tree.

Larix species are attacked by the Larch Sawfly (Pristiphora erichsonii). The adult wasp-like fly deposits eggs in an incision on the twigs during late spring and the 25mm long olive green spiny larvae chew the needles. The larvae overwinter on the ground in brown cocoons.

Melaleucas are also attracts the Paperback Sawfly.

Pinus and Callitris species are attacked by up to four species including the Pine Sawfly (Diprion simile).

Sorbus aucuparia is attacked by the Mountain Ash Sawfly (Pristiphora jeniculeta). The larvae feed on the leaves, leaving only the mid rib and main veins.  Heavy infestations causes serious defoliating of the tree.

Viola species are attacked by the Sawfly (Ametastegia pallipes)  which eats the leaves skeletonising them.

Damage Caused

Generally the larva eat the surface of leaves, skeletonising them when young, but as they develop they eat large pieces leaving only the mid rib. They tend to feed on the terminal shoots, and heavy infestations can defoliating young trees.

Cultural Control

Clustering larvae may be hosed or knocked from branches, falling to the ground where they can be squashed under foot or attacked by other predators. At night when the larvae congregate they can be collected and disposed off. In small infestations they can be picked by hand and destroyed.

Biological Control

The exudate causes most birds to avoid the larva, although cockatoos remove the head and oil gland prior to consumption. They are also eaten by lizards and frogs or attacked by parasitic wasps.

Chemical Control

Affected plants can be sprayed using Maldison or Carbaryl, this is only possible for small trees.

Note

Always read the label for registration details and direction of use prior to application of any chemicals.

PEST

   NAME

     Aphids

     Various Aphid Species

   ORDER

     Hemiptera

   FAMILY

     Aphididae

Description of the Pest

The common name varies and aphids may be referred to as black fly, greenfly, ant cows or plant lice.

These small insects have soft globular body that is from 1mm to 8mm long and vary in colour from green, yellow, black and pink, with the winged forms being elongated. Both adult and nymphs, have piercing and sucking mouthparts.

Aphids are found on buds, flowers, or leaves and stems, preferring soft new growth. On older leaves the aphids are found in protected positions, such as under the leaf. Certain species of aphids form galls as they suck sap and may be found on the roots of the plant. (E.g. Woolly aphids and Black peach aphids)

Most aphids possess a pair of characteristic tubular projections, known as cornicles; these secrete a pheromone and a waxy fluid, which is thought to protect them from some of their predacious enemies.

White exoskeletons, honey dew and sooty mould indicate the presence of Aphids

Balsam Twig Aphid (Mindarus abietinus) is greenish and covered in a white wax and is normally found on the young shoots of conifers bending and killing the needles. It is found on Abies and Picea species.

Aphid and their exoskeletons    on underside of a leaf

Black Citrus Aphid (Toxoptera aurantii) has a soft plump green body and the black coloured adults may or may not be winged. They feed in groups, curling leaves and producing honeydew attracting sooty mould.

Green Peach Aphid (Myzus persicae) is a soft plump green insect up to 0.2mm long and may be wingless. The nymphs are yellowish green and are responsible for spreading viruses in Dianthus species.

Spruce Gall Aphid (Chermes abietis) form cone shaped galls up to 12mm long resulting from the feeding. The wingless female adult lays eggs on the stems and the immature females overwinter on bud scales. Large infestation will weaken trees such as Picea abies and Pseudotsuga menziesii.

Tulip Bulb Aphid (Anuraphis tulipae) is small, waxy grey coloured and infests the underside of the bulb scales or rhizomes. They occur in the ground or on above ground parts and during storage.

Life Cycle

These insects have a Hemimetabolous life cycle, i.e. The nymphs resemble the adults.

During spring all eggs produced hatch as female nymphs. Adult Aphids are capable reproducing without fertilisation.  The males are only produced in some species as the weather cools down, and the day length shortens.

Aphids are capable of giving birth to living young and large populations build up quickly during summer. Over crowding causes the aphids to become smaller, less fertile and produce more winged forms that can migrate to other host plants.

There are many different types of aphids and the life cycle varies from warm to cold climates.

Typical life cycles

Distribution of the Pest

World wide

Period of Activity

In warm climates they are seen throughout the year, but aphids dislike hot dry or cold conditions and heavy rain will decrease the population. In cold areas aphid eggs are laid around a bud base or other protected areas of the plant during autumn and emerge as nymphs during spring, feeding on the new growth.

Numbers build up quickly in the warmer months of the year. Some species feed during winter on Sow thistles.

Susceptible Plants

There is a wide range of plants attacked, from roses to vegetables, shrubs and trees. Certain aphids attack a specific genus while others have a wide range of host plants. Many are capable of transmitting plant virus diseases.

Adults and nymphs feeding    A colony of aphids

Acer species are attacked by several aphids including the Norway Maple Aphid (Periphyllus lyropictus) which is a greenish with brown markings and secret honeydew, preferring Acer platanoides. Other aphids include (Drepanaphis acerifolia) and (Periphyllus aceris) which are commonly found on the underside of leaves.

Acer species are also attacked by the Woolly Maple Aphid (Phenacoccus acericola) which covers the undersides of the leaves with a cotton-like mass

Alnus species are infested with the Alder Blight Aphid (Prociphilus tessellates) which is blue-black adult that forms woolly masses on the down-turned leaves. The nymphs overwinter in bark crevices.

Aquilegia species are attacked by several aphids including (Pergandeidia trirhoda) which is a small, flat cream coloured insect that is found on young branches and the underside of leaves.

Betula species may be attacked by the European Birch Aphid (Euceraphis betulae) which is small and yellowish or the Common Birch Aphid (Calaphis betulaecolens) which is large and green producing ample honeydew for sooty mold to grow on.

Callistephus species may be attacked by the Corn Root Aphid (Anuraphis maidi-radicis) causing the plant to become stunted, the leaves wilt and turn yellow. The aphids feed on the roots producing honeydew and are dispersed to other host by ants. It is also attacked by the Potato Aphid (Macrosiphum solanifolii).

Carya species are attacked by Gall Aphids (Phylloxera caryaecaulis) which is found on the leaves, twigs and stems forming galls and turning them black.

Chaenomeles and Gladiolus species, new growth and leaves become infested with the aphid (Aphis Gossypii)

Cupressus macrocarpa may become infested with the Cypress Aphid (Siphonartrophia cupressi).

Cyclamen species are attacked by the aphid (Myzus circumflexus) and (Aphis gossypii) which can infest healthy plants.

Dendranthema, Dianthus  and Crocus species are attacked by several types of aphid including the Green Peach Aphid (Myzus persicae) and the Chrysanthemum Aphid (Macrosiphoniella sanborni).

Hibiscus species are attacked by the aphids (Aphis craccivora)  and (Aphis gossypii), both congregate towards the branch tips and may cause leaf curl. Normally only seen in sub-tropical climates.

Aphids on a stem    Mandevilla species

Larix species is attacked by the Woolly Larch Aphid (Adelges strobilobius). The winged adults deposit eggs at the base of the needles during spring and white woolly areas appear attached to the needles where the adult aphids feed. The young aphids overwinter in the crevices of the bark.

Mandevilla species is attacked by aphids that congregate towards the branch tips and may cause leaf curl.

Pinus species is attacked by several species of aphid including Pine Bark Aphid (Pineus strobi), Pine leaf Aphid (Pineus pinifoliae) and the White Pine Aphid (Cinara strobi).

Primula species are attacked by four species of aphid including foxglove, and green peach aphid.

Rudbeckia, Delphinium, Chrysanthemum and Helianthus species are attacked by a bright red aphid (Macrosiphum rudbeckiae).

Sorbus aucuparia is affected by the Rosy Apple and Woolly Apple aphid which attacked the foliage and young shoots.

Spiraea species are attacked by the Aphid (Aphis spiraecola) which feeds on the young shoots and flowers.

Tropaeolum species are attacked by the Black Bean Aphid (Aphis fabae), which is found in large numbers on the underside of the leaves, turning them yellow and causing them to wilt then die.

Tulipa, Iris, Freesia, Gladiolus and Zephyranthes species are infested with the Tulip Bulb Aphid.

Ulmus species are infected by two types the Woolly Apple Aphid (Eriosoma lanigerum), which curls and kills young terminal leaves and the Elm Leaf-Curl Aphid (Eriosoma ulmi) which occasionally attacks the trees.

Viburnum species are attacked by the Snowball Aphid (Anuraphis viburnicola). This aphid congregates at the end of the branches causing the leaves to curl and become deformed under which they hide.

Aphids on Quercus robur

Damage Caused

Buds that have been attacked may not open, leaves and twigs become twisted or distorted and wilt. The aphids also produce honeydew, which is sticky and attracts sooty mould (fungus). This fungus forms a thick layer over the leaf, fruit or stems reducing the plants photosynthesis capability. The sooty mould spoils the plants appearance and its fruit, as does the insects white exoskeletons.

Control

Cultural Control

Aphids may be removed from a plant by hosing them off with water (limited success) or applying soapy water to aphids.. Another organic sprays can be efficient in controlling aphids. Aphids  may also be removed physically by hand for small colonies on spine less plants. Species that live under ground are difficult to control but cultivation of the surrounding soil may help in controlling the infestation. (limited mainly to annual or commercial crops)

Reflective mulch around the plants also reduces numbers by repelling the insect this material is available commercially. (Reflective mulches are mainly used in market gardens for avoiding the Green peach Aphids) Resistant rootstocks are available to avoid some root feeding aphid of commercial plants, e.g. Vines and fruit trees

Biological control

Aphids are attacked by several insects includes parasitic wasps or predators such as ladybirds/ lady beetles, hover flies, lacewings, spiders.

   Parasitised aphids

Chemical Control

Aphids may be controlled by spraying with a contact or systemic insecticide. The type of application used will depend on the plant is being attacked.

Aphids can be suffocated and therefore controlled with the use of e.g. White oil, Pest oil, Soapy water from soap such as Lux Flakes ®

Note

It is your responsibility by law to read & follow the directions on the label of any pesticide

Monitoring

Aphid are attracted by yellow colour and traps such as boards painted yellow and covered in glue or sticky substance will attract and trap the insects.  There is also a commercially sticky yellow tape that can be attached to susceptible plants

Amendments by B. Sonsie Dip Hort Sc Burnley

PEST

   NAME

     Budworms

     Helicoverpa species

   ORDER

     Lepidoptera

   FAMILY

     Noctuidae

Description of the Pest

Mature larvae are caterpillars up to 45 mm long; colour varies from yellowish-green to reddish-brown, most with stripes or darker body markings. Female moths have a wingspan up to 40 mm across, are reddish brown in colour; hindwings are pale at the base and dark along the edges.

Moths of Heliothis are very similar to that Helicoverpa armigera (Corn earworm).

Helicoverpa have a spot which is kidney shaped in the centre of the forewing,

The Adults of all species are attracted to lights at night.

                 

The larvae are smooth and vary in colour but have light coloured strips

Life Cycle

This insect has a Holometabolous life cycle, i.e. it has a larval and a pupal stage.

Females lay up to 1000 tiny white eggs, deposited singly, on the young growth of host plants.

Larvae pupate in the topsoil, after feeding for 2-3 weeks; the emergence of adults is triggered by appropriate moisture & temperature conditions during Spring. Long periods of cold and drought can delay the emergence of the adult moths for up to 5 months.

There are two main periods of infestation early summer and autumn.

Distribution of the Pest

Helicoverpa species (Heliothis species) are found throughout Australia.

Larvae have prominent prolegs

Period of Activity

Most active in Spring and Summer, after good rainfall and vigorous plant growth.

Damage Caused

Larvae attack chew on new growth, fruit, seed and flower buds. Fruit and flowers are damaged and yield is reduced. Entry holes in fruit enlarge and become more obvious as the caterpillar matures.

Bud worms which feed inside the flower buds can cause the buds to brown and not open.

Damage to a flower bud

Susceptible Plants

Attacks a wide range of fruiting and ornamentals plants, such as gardenias, carnations, roses, calendula, hollyhocks, snapdragons, etc. This is a major pest of commercially grown tomatoes, beans,

sweet corn, cotton, sorghum and peas.

Pseudotsuga menziesii, Picea, Pinus, Pseudolarix and Tsuga species are attacked by the Spruce Budworm (Choristoneura fumiferana). Symptoms include the new opening buds and needles are eaten by the dark red caterpillar that has a yellow stripe along its side. It is a serious pest to ornamental and forest trees and control is difficult.

Control

Cultural Control

It is difficult to control bud-worms once they enter the fruit or buds so it important to apply clay and pepper sprays or pyrethrum, while the young lava are feeding on the leaves.  Caterpillars may be removed by hand or infested flowers and fruit removed from the plant.

Biological Control

Genetically modified crops have been developed for cotton.

A virus NPV may be commercially available for cotton growers to control Helicoverpa armigera and H punctigera

Helicoverpa armigera & Helicoverpa punctigera), are parasitised by many different insects, including Chaetophthalmus dorsalis flies from the Tachinidae family.

Egg parasites include Trichogramma & Telenomus wasps

Larval parasites include         Micrropilitis demolitor, Netelia producta and Trachnid flies

Larval pupa parasites include Heteropelma scaposum and Lissopimpla excelsa

Pupal parasites include Ichneumon promissorius

Chemical Control

Control needs to occur before the larvae enter the fruit or flowers.

Note

It is your responsibility by law to read & follow the directions on the label of any pesticide

Monitoring

Shake plants twice a week on to a stiff white cardboard, once they start flowering.

Other Common Names; includes

Native Budworm (Helicoverpa punctigera) Tomato grub, Cotton bollworm, Corn ear worm, Tobacco budworm

Amendments by B. Sonsie Dip Hort Sc Burnley

PEST

   NAME

     Cypress Bark Weevil

     Aesiotes leucurus

   ORDER

     Coleoptera

   FAMILY

     Circulionidae

Description of the Pest

The adult is up to 200mm long, greyish brown in colour, with white leg joints and white-tipped wing-covers, and two pairs of blunt spines on the back. Adults and larvae have chewing mouth-parts.

Appearance of the Pest

This insect has a Holometabolous life cycle, ie. When metamorphosis is observed during the pupal stage.

Larvae feed under the bark of susceptible plants. Discoloured foliage may indicate the presence of larvae, although damage may not be apparent until die-back occurs, or the branch falls. Larvae pupate in a chamber hollowed out in the sap-wood and lined with wood shavings.

Period of Activity

Larvae are active through spring and summer; they may be seen throughout the year in warm climates.

Susceptible Plants

Many plants are attacked including Cypress pines and occasionally Pinus and Chamaecyparis species are attacked during particularly during drought periods.

Damage Caused

Loss of foliage colour. Larvae feed in the phloem-cambium region, beneath the bark, and may girdle the branch, causing ring-barking. Adults chew bark and may damage small branches.

Control

Remove damaged bark and timber. Improve the culture of the plant by maintaining appropriate feeding and watering, and removing or repairing damaged limbs.

DISEASE

   NAME

     Fungi (General)

     Various Fungal species

Description

A fungus is a plant that lacks chlorophyll and conductive tissue. Generally they are made up of branched threads called 'hyphae' and collectively form a vegetative body called 'mycelium'. The fungus is small but the fruiting bodies can become very large up to 600mm across such as bracket fungi or mushrooms. Common fungi are mould and mildews. problem that attacks the roots causing them to rot.

Fungus can reproduce many ways but primarily it is asexually, simular to cuttings of a plant and often occurs with minute portions of the mycelium (spores) separating. The spores can be arranged in a structure such as a sporangia or pycnidia or develop without an enclosed structure called a "conidia". Either way the fungus propagates very rapidly.  Sexually reproduction occurs when two nuclei unite and form sexual fruiting bodies (zygospore).

Strelitzia reginae flower

Symptoms

Fungus attacks all the above or below ground level parts of the plant living within the tissue of the plant and are very small and not normally detected until the fruiting body appears. However parasitic types such as powdery mildew or rust are visible on the outer surface of the plant.

Fungi hyphae may be divided by cross walls and known as "septate" while others with no cross walls are known as "nonseptate". These are the fungi responsible for cell leakage as in rot.

Back Mold (Chalariopsis thielavioides) affects understocks of grafted Rosa species by inhibiting the development of callus. It is whitish-grey maturing to black and can be found in the pith of the rose stem.

Black Root Rot (Chalara elegans).This recently introduced fungal disease in Australia (1993) affect plants by blackening the root systems and turning leaves yellow or purple. It is difficult to identify specifically as other pathogenic root diseases and nutritional deficiencies have simular characteristics.  

The asexual spores are dispersed by wind or water. It is also transmitted on insects and in contaminated growing media or plants preferring humid moist conditions.

This fungus affects a wide range of ornamental plants including; annuals, perennials and shrubs. Examples are Begonia, Boronia, Camellia, Cyclamen, Fuchsia, Gerbera, Grevillea, Impatiens, Pansy, Petunia, Rosa species and Snapdragon.

Black Stem Rot (Pythium splendens) normally is a rot that occurs in cuttings turning the stem progressively black and shrunken. The leaves fall and the plant becomes stunted, eventually dieing.

Bleeding Necrosis (Botyosphaeria ribis) attacks and kills the inner wood causing the bark to split open and bleed sap giving it an oily appearance.

Blight (Endothia parasitica) is a serious pest of Castanea species, entering the twigs and small branches, and then progressively travelling throughout the tree killing it. It may form cankers on the base of the trunk or in the dead branches above with the amber coloured fruiting bodies pushing there way through the bark.

Copper Web ((Rhizoctonia crocorum). This fungal disease appears in defined patches causing the corms in the centre to become a black powdery mass. Corms on the outer ring of the patch that are partially infected forming a felty mass of violet threads on the corm scales. These threads extend into the soil and large sclerotia forms in the soil and on the corms. Healthy corms become infected from contaminated soil that contains mycelium and sclerotia.

Dry Rot (Phyllosticta concave) forms small circular spots that increase to a diameter of 30mm, and then becomes sunken as the cells collapse. The infected area develops minute black fruiting bodies.

Dutch Elm Disease (Ceratocystis ulmi) is a serious fungal problem of Ulmus species that initially causes yellowing then wilting of the leaves that turn brown and die. This may be seen on certain branches of the tree and on inspection under the bark the sapwood reveals brown streaks. A cross section of the affected branch displays round spots that are dark brown. This infection normally spreads quickly throughout, killing the tree in one to two seasons.

Dieback in Camellia (Glomerella cingulate) is a pathogenic fungus that infecting existing wounds such as leaf scars or mechanical damage, forming a sunken area (canker) that spreads around the stem causing die back. The affected plant has new shoots that are brown-black and the tips curl, forming a 'Shepard's Crook' appearance. The leaves also die but are persistent on the plant and the spores are found in soil or on other infected plants.

Curvularia Leaf Spot (Curvularia species) in Turf Grass. This is normally a secondary weak fungal infection that forms spots on the leaves that lengthens turning the leaves greyish. The leaf shrivels then dies and infected areas appear as weak patches in the turf. Preventive measures include minimising leaf wetness and excessive use of nitrogen fertiliser.

Fairy Rings Blue Couch     

Fairy Rings are a fungal problem in Turf Grass and is caused by several species including (Lycoperdon species), (Marasmius species) and (Tricholoma species). Rings appear in the turf as fruiting bodies or dead grass and as lush green foliage. The mycelia expand radially in the turf feeding on soil nutrients and organic matter with water present.

Under severs conditions the mycelia consume all available nutrients resulting in the death of the turf. Lush turf can result from a less developed infection, where the decomposing hyphal releases nitrogen. This available nitrogen may be beneficial to the turf but some forms of nitrogen are detrimental.

Leaf Blister (Taphrina coerulescens) appears as yellowish circular raised areas on the upper side and depressions on the underside of leaves, up to 15mm across. As the fungus spreads the leaf dies but remains attached to the tree and this infection is commonly found on Quercus species..

Leaf Blotch (Guignardia aesculi) forms small or large water soaked spots that are reddish with a bright yellow margin and form black fruiting bodies in the centre. The affected leaf and petiole have a scorched appearance before falling, found on Aesculus species

Grevillea robusta     Leaf Scorch

Leaf Scorch (Verrucispora proteacearum) is a fungal disease that infects leaves causing large parts of the leaf to turn grey-brown, giving the appearance that it has been singed by fire. Black fruiting bodies appear on the affected areas and the leaf soon withers then dies. New, mature leaves are affected during very wet periods towards the end of the branches and Grevillea and Hakea species are susceptible.

Melting Out (Helminthosporium vegans) forms bluish black spots with straw coloured centres on the leaves and may be found on the sheath, encircling it causing Foot Rot. It infects grasses particularly Poa pratensis. There is another fungus that is simular Helminthosporium Blight (Helminthosporium dictyoides) that infects Poa, Festuca and Agrostis species.

Pad decay (Aspergilus alliaceus) infects Cereus and Opuntia species and occurs at during periods of high temperature.  The yellow spores at the epidermal layer through wounds and germinate on mass causing the area to become soft and spongy. An anthracnose called Shot Hole is a similar forming brownish spots the turn grey, and then black destroying pads. Control methods include physically removing damaged pads and allowing the Sun to heal wounds.

Potato Gangrene (Phoma foveate) is a soil borne fungus that infects the roots during harvest primarly through wounds and develops during storage. The potatoes rot from the inside forming rounded depressions on the surface and have a strong odour of rotten fish.

Root Rot Fungi (Phymatotrichum omnivorum) and (Pellicularia filamentosa) cause the roots to rot and the plant suddenly wilts then dies.

Root Rot (Pythium debaryanum) forms water soaked dark brown streaks that affect all parts of the plant causing wilting then dieing. It infects Ranunculus species, it also infects cactus species by forming brown spotting and wilting that appears at the base of the plant then extends towards the top. It quickly spreads from plant to plant in collections and is controlled by avoiding over watering, excessive humidity and are using a sterilised soil when potting up.

This fungus also is responsible for damping off of seedlings in a glasshouse environment.

Spring Dead Spot     

Spring Dead Spot (Leptosphaeri species) is a fungal disease that infects Couch Grass. It first appears during autumn as pale bleaches areas up to 500mm (20in) wide and persists throughout winter. In spring the affected areas do not recover or recover slowly and on inspection the roots or rhizomes are rotted. Runners from the surrounding healthy turf will help with recovery and all signs of the problem disappear by mid summer.

Cactus species      Pachypodium species

Stem Rot (Helminthosporium cactivorum) forms well defined yellow lesions that mature into soft dark brown rot. It commonly infects Cactus species entering through the stomates or wounds. Heavily infected plants collapse and die.

Stem Rot or Basal Rot (Pellicularia rolfsii) is a soil borne fungus that infects the stem root junction and extends into the leaves. In orchids the leaves become discoloured, dry and detach from the base which is covered in a fungal growth that produces sclerotia. The sclerotia is whitish to yellow then becoming dark brown and can be viable for up to four years.

White Mold  (Ramularia desta f. odorati) occurs on both sides of the leaf and looks simular to powdery mildew but forms faint dull, reddish brown elongated spots on the leaf that may be depressed or along the margin where they have a watery appearance. Tufts of hyphae develop in the stomates.

Wilt (Ceratocystis fagacearum) causes leaves to curl then turn brown and the sap wood may also turn brown or black. Heavy infection may kill a tree within two seasons and is found on Quercus species and other ornamental trees.

Witches Broom may be a fungal problem that causes a proliferation of small axillary shoots to appear at the end of the branches. Little is known about this problem, though it affects a wide range of plants including Eucalyptus, Leptospermum and Pinus species.

Source and Dispersal

Fungus is found in the soil or on other infected plants and after releasing the spores, they are dispersed by wind or are transmitted in infected stock, insects and with splashing water.

Wilt is transmitted by infected root stocks, several species of insect and contaminated tools.

Dutch Elm Disease is transmitted by bark beetles such as (Scolytus multistriatus) and (Hylurgopinus rufipes). These beetles deposit eggs in the sapwood where the lava tunnel and pupate. The emerging beetles tunnel the bark and carry the fungus to fresh feeding sites on the tree. Infected beetles may also be transported to fresh sites in waist material.

Favoured Conditions

Prefers cool moist conditions with temperatures from 10º to 25ºC and is more common from autumn to spring when it is wet.    

        

Affected Plants

A wide range of plants and all parts can be infected by various fungal diseases. Bleeding Necrosis is found in Liquidambar species and Stem Rot or Dry Rot infects Cactus species such as Opuntia and Pelargonium.

Abies species are infected by several fungi that cause Leaf Cast which turn the needles yellow to brown then fall prematurely.

Abutilon species are infected by the Stem Rot (Macrophomina phaseolin) affecting the lower stems and is not commonly seen.

Achillea, Cuphea, Leucanthemum, Euphorbia species are infected by the Stem Rot (Pellicularia filamentosa) which enters through the roots and rots the base of the stem.

Alternanthera species are infected by the Leaf Blight (Phyllosticta amaranthi) which forms small brown spots on the leaves causing them to curl and die.

Aloe, Astrophytum, Copiapoa, Echinocactus, Espostoa, Ferocactus, Gymnocalycium, Kalanchoe and Schlumbergerera species are infected by Bipolaris Stem Rot (Bipolaris cactivora). This infection affects many cacti species causing rot in the stems with a blackish appearance.

Amelanchler is affected by the Witches Broom (Apiosporina collinsii).

Antirrhinum species are infected by the Blight (Phyllosticta antirrhini) that forms light brown spots on the upper-side of the leaf and on the stem. As the spots enlarge they turn greyish with black fruiting bodies in the centre, then become brown and killing the affected areas.

Begonia species are infected by the Stem Rot (Pythium ultimum) turning stems black then becoming soft and causing the plant to collapse. This is the same fungus that causes Damping-off.

Betula species are affected by the Leaf Blister (Taphrina bacteriosperma) which curls the leaves and forms reddish blisters.

Chamaedorea and other cain-like species are infected with Gliocladium Stem Rot (Gliocladium vermoseni) which forms a dark basil stem rot generally on damaged plants and produces orange-pink spores.  The mature leaves are first affected and eventually the stems or cains rot and die.

Crocus and Gladiolus species are infected by the Dry Rot (Stromatinia gladioli), which causes lesions on the corms and rots the leaf sheath.

Crocus, Iris, Tulipa, and Narcissus species are infected Copper Web ((Rhizoctonia crocorum).

Dianthus species are infected by Phialophora Wilt (Phialophora cinerescens) that causes the leaves to fade and plants to wilt. There is obvious vascular discoloration which is very dark. It is not found in Australia.

Erythrina x sykesii may be infected by the Root Rot Fungi (Phymatotrichum omnivorum).

Fern species are infected by Tip Blight (Phyllosticta pteridis). This blight produces ash-grey spots with purple brown margins and the fruiting bodies appear as black pimple like spots.  It is transmitted by air or moisture and in infected fronds become brown and die.  Control methods include sprang fungicide on leaves or reducing humidity and avoid wetting the fronds.

Forsythia species are infected by Stem Gall (Phomopsis species). It forms rounded growths along the stems causing them to die and look unsightly.

Gladiolus species are infected by Penicillium Rot of Corms (Penicillium gladioli). This disease forms deeply sunken reddish brown areas that become corky and produce a greenish fungal growth.

Hedera species are susceptible to several Fungal Leaf Spots including (Glomerella cingulate), (Phyllosticta concentrica) and (Ramularia hedericola). All of which cause yellowish spots that develop into dry brown blotches that kill the leaf.

Larix species are susceptible to Leaf Cast (Hypodermella laricis). This fungus attacks the needles and spur shoots turning them yellow at first then brown after which small black fruiting bodies appear on the leaves during winter.

There are several other fungi including (Cladosporium species) and (Lophodermium laricis) cause leaf blight or leaf casts.

Orchids such as Cattleya, Cymbidium, Cypripedium, Dendrobium, Epidendrum, Oncidium, Paphiopedilum, Phalaenopsis and Zygopetalum species are infected by Phomopsis Rot (Phomopsis species). This fungal problem forms a firm brown rot that appears on the leaves, pseudobulbs and rhizomes. The affected areas have yellow margins and the centre is covered in tiny black specks (fruiting bodies). Cattleya species are particularly susceptible. These plants are also infected by Psudobulb Rot (Mycolleptodiscus coloratus implicated). Dark spots appear on the pseudobulbs eventually causing extensive rot and killing the bulb.

Palms are infected by the fungus Butt Rot (Ganoderma sulcatum). The fungus entered the lower trunk normally as a result of mechanical damage (lawn mower). Symptoms include stunting of new growth and yellowing of the lower leaves. Fruiting bodies become evident at the base of the trunk. There is no effective control method and replanting in infected soil should be avoided.

Kikuyu Yellows     

Pennisetum clandestinum (Kikuyu) is susceptible to Kikuyu Yellows (Verrucalvus flavofaciens), thisis a water mould that infects the roots and causes them to rot. The infection extends up the stem and onto the leaves with yellow discolouration and can be limited to a small or large area up to 1m (3ft) wide.

It is found in warm temperate to sub tropical regions and dispersed in infected soil or plant material. There is no chemical control, nitrogen fertiliser masks the symptoms and complete fertiliser encourages stronger roots to fight the disease.

Pittosporum, Antirrhinum, Aquilegia, Echinops and Orchid species are infected by the Stem Rot or Basal Rot (Pellicularia rolfsii) commonly in the northern hemisphere and preferring humid glasshouse conditions.

Solidago species are infected by the fungal Scab (Elsinoe solidaginis) which covers the leaves and stunts the growth of the plant. Young plants may be killed.

Trillium species are infected by the stem rot (Pellicularia rolfsii) and ( Ciborinia trillii). This normally occurs in wet soils and is detrimental to the plants life.

Tsuga species are infected by Sapwood Rot or Butt Rot (Ganoderma lucidum) and (Coniophora puteana), which attacks the sapwood close to the bark, towards the base of the tree. Commonly killing the host.

Tulipa species are affected Blue Mold (Penicillium species) and the fungus (Rhizopus stolonifer) causing rot in the bulbs.

Vinca species are infected by the soil born Root Rot (Pellicularia filamentosa) which rots the stems and roots.

Viola species may be infected with the Scab (Sphaceloma violae) which attacks all parts of the plant including the seed capsule forming yellowish spots that turn brown and in leaves fall out. Stems and petioles can be girdled killing the upper part.

Viola species are also infected with the Stem Rot (Myrothecium roridum) which attacks the stems at ground level causing them to become dry and brittle. The leaves show symptoms by turning purplish-black and this fungus also infects Alcea and Antirrhinum species.

Non-chemical Control

Generally remove and destroy any infected plants or plant parts, when replanting, avoid using susceptible species for 3 years.  When growing crops space the plants to reduce the humidity and airflow and cultivate the soil to increase the drainage.  Remove weed growth from around the susceptible plants.

Avoid over watering the surrounding soil which encourages fungal development. In the case of trees remove any infected branches and heavily infected trees should be cut down and removed. This infected material should be disposed or burnt. Damaged trees should have the wounds dressed and sealed as a preventative measure particularly for Dieback in Camellia.

Deter Potato Gangrene by planting clean stock and be careful not to damage the crop when weeding. When harvesting the tubers choose a dryer period and be careful not to damage them.

     Fairy Rings

Fairy Rings in Turf are difficult to control and may appear or disappear sporadically. Cultural practice such as minimal thatch build-up, regular aeration and a reduction of organic matter spread on the turf will reduce infection.

Chemical Control

No suitable fungicides available, though drenching or spraying the soil with the fungicide dichloran helps control soil born fungi.

Note

Always read the label for registration details and direction of use prior to application of any chemicals.

DISEASE

   NAME

     Canker (General)

     Various Canker Species

Description

This is a fungal problem that enters the plant through wounds causing dieback of twigs and stems.

Symptoms

The stems become discoloured (pale brown) usually from a pruned point, working its way down the stem and normally intersecting or surrounded with live cambium. The bark splits or cracks, foliage dies and infected areas can develop tiny black fruiting bodies. Heavy infected plants eventually die, though certain varieties are resistant halting the spread of the infection.

                 

Black Canker (Phyaslospora miyabeana) forms dark brown spots with concentric rings on the upper leaf surface and grey spots on the stems. The tiny black fruiting bodies develop in the stem lesions. It is found on Salix species and persistent attacks will kill the tree.

The Canker (Cytospora valsa) causes the browning and death of branches in Picea abies and Picea pungens. This infection occurs normally from the base of the tree with infected needles falling, and white resinous patches appearing on the bark accompanied by cankers with tiny black fruiting bodies.

The Canker (Corynneum cardinale) is a casual fungus that invades wounds and infects living bark and associated cambium turning the foliage yellowish. As it spreads it girdles the branch killing it and ultimately the top of the tree dies out. Cankers eventually form in the trunk and ooze resin. It is found on Cypress.

   Platanus x hybrida

Cankerstain (Ceratocystis fimbriata f. platani) forms sunken cankers on the trunk and large limbs forming longitudinal cracks and roughened bark. Infected areas form callus around the margins which dies off and when cut open, dark coloured streaks are revealed extending to the central pith. These streaks then radiate out into uninfected wood resulting in the thinning of the crown and producing unusual small leaves. It is normally transmitted through poor tree surgery techniques and infected tools.

Cytospora Canker

Cytospora Canker (Cytospora chrysosperma) is a casual fungus that infects the young twigs, then moving to the stems, branches and trunk causing brown sunken areas to appear that is covered in red pustules. The fungus tends to attack trees that are in poor health. Control requires the removal of infected branches and improved culture to regain the plants vigour. Sorbus aucuparia, Salix and Popular species are susceptible.

Cypress Canker

Cypress Canker (Seiridium species) enters the plant through wounds or through insect damage causes the bark to spread revealing brown powdery spores that are accompanied by oozing resin. The canker eventually girdles the branch or trunk causing ringbarking and the death of the plant.

Nectria Canker (Nectria Cinnabarina) forms cankers on the twigs and small branches producing red fruiting bodies and eventually killing the tree. It is found in many parts of the world infecting a range of trees including hardwoods.

          Populus nigra

Poplar Canker (Cryptodiaporthe populea) infects the cambium layer damaging the bark and sapwood where the elongated sunken canker forms. Branches are girdled causing the upper portion to die off. This is a serious problem for Populus nigra var. Italica entering the plant through wounds or the leaves then spreading to twigs and branches. Control is difficult as removal of infected parts will not eradicate the problem, but encourage it. Young plants may be sprayed with a copper based fungicide to reduce leaf infection and heavily infected plants should be removed the burnt.

Stem Canker of Red Flowering Gum (Sporotrichum destructor) enters through wounds in the bark forming cankers in the trunk and branches, splitting the bark apart, revealing the wood and infesting the surface with powdery spores. This infection causes the leaves to wither and then the branches die, eventually killing the tree.

Stem Canker (Strumella coryneoidea) is a casual fungus that forms on the trunks of trees as a smooth, dispersed or sunken infection. On mature trees the infection sheds the bark with the canker forming callus tissue around the margins and the centre being exposed. These cankers then tend to extend up and down the trunk, only girdling over a long period of time. It is found on Quercus, Fagus, Aesculus species, and Acer rubrum , Nyssa sylvatica, Carya ovata and Morinda citrifolia.

Source and Dispersal

The spores are found on infected dead plant material and can be dispersed by wind and with splashing water.

Favoured Conditions

It prefers a warm humid conditions and plants that have a wounds derived from poor pruning techniques and insect or other damage, especially if water is allowed to settle on the wound.

        

Affected Plants

Cankers may infect a wide range of trees and shrubs with some species being specific to its host. Examples are listed below.

Abies species are infected by several cankers including (Cytospora pinastri), (Cryptosporium macrospermum) and (Scoleconectria balsamea). These fungi form dead sunken areas on the trunk and branches.

Alnus species are infected by a few cankers including (Nectria coccinea) and (Physalospora obtusa) these attack the branches causing die back.

Betula species may be infected by the Canker (Nectria galligena) that occurs in the forks of trees causing splitting and cracking of the bark by swelling, to reveal the canker. Callus rings may form around the affected areas as a defence mechanism triggered by the tree.

Buxus species are infected by the Canker (Pseudonectria rousseliana) which shows signs of poor new growth during spring with the leaves turning from light green to a tan colour. These leaves tend to lay flat along the stems and reddish pustules appear both on the stems and leaves. The bark becomes loose and on inspection reveals a darkish colour underneath. It is difficult to control and the canker can kill the plant.

Castanea species are infected by the Twig Canker (Cryptodiaporthe castanea), a fungal problem that causes significant damage to the twigs and small branches, but tends to attack stressed trees.

Cercis and Ribes species are infected by the Canker (Botryosphaeria ribis) which forms small sunken areas on the stems causing wilting and eventually killing the branch by girdling. The cankers turn the bark black then split it open and the adjoining wood becomes discoloured. This is a serious problem for this and many other plant species.

Cotoneaster, Betula, Catalpa and Aesculus species are infected by the canker (Physalospora obtusa).

                  Cypress Canker

Cupressus species and Chamaecyparis lawsoniana are susceptible to Cypress Canker (Seiridium species) which causes leaf browning and then girdles the trunks resulting in ringbark. There is also another Canker (Coryneum cardinale) that has simular characteristics and is found in the northern hemisphere.

Cupressus sempervirens is infected by Cytospora Canker (Cytospora cenisia var. littoralis).

Larix species are susceptible to several fungal cankers including (Trichoscyphella wilkommii), (Trichoscyphella ellisiana), (Aleurodiscus amorphus), (Leucostoma Kunzei) and (Phomopsis spp.)

Nyssa sylvatica is attacked by three cankers including (Strumella coryneoidea).

Pinus species are infected by many types of cankers.

Platanus species are infected by Cankerstain.

Cytospora Canker on Salix babylonica

Pseudotsuga menziesii Douglas Fir is attacked by several cankers including (Cytospora species), (Dasyscypha ellisiana), (Dasyscypha pseudotsugae), (Phacidiopycnis pseudotsugae) and (Phomopsis lokoyae). These infections normally do not require control and are more prevalent on the coastal form.

Salix and Populus species are infected by several cankers including Cytospora Canker (Cytospora chrysosperma), Hypoxylon Canker (Hypoxylon pruinatum), Septoria Canker (Mycosphaerella populorum) and Branch Gall (Macrophoma tumefaciens). Many of these fungi can cause the death of the plant.

Thuja orientalis, Cupressus and Juniperus species are infected by the canker (Corynneum cardinale).

Tilia and Acer species are infected by (Nectria cinnabarina) attacking twigs or branches.

Tsuga species are infected by several cankers including (Dermatea balsamea) and ( Cytospora species).

Ulmus species are infected with up to eight fungal cankers including (Apioporthe apiospora) and (Nectria coccinea).

Vaccinium ovatum is infected by the canker (Coryneum microstictum) which attacks the stems.

Vinca species are infected by canker-dieback (Phomopsis livella) causing the shoots to wilt, turn brown and die. This can reduce the plant to ground level, and normally occurs during rainy periods.

Non-chemical Control

It is very difficult to control and correct pruning techniques with sharp tools for repairing wounds or prune well below the infected areas. Ensure that there are no ragged edges on the cuts and the angle should cut allows water to run off or dress the wound. Plant resistant varieties when available. Heavily infected trees should be removed to avoid spreading the disease.

Improve the culture of the affected plant to increase vigour for greater resistance.

Chemical Control

There is no satisfactory chemical control and prevention is imperative.

Note

Always read the label for registration details and direction of use prior to application of any chemicals.

DISEASE

 

   NAME

     Rust (General)

     Various Rust Species

 

Description

Generally this fungal problem involves many species causing a range of symptoms, but generally produces pustules that release reddish - brown spores. Most fungus is specific to its host and normally will not infect other plant species.

 

Pustules

 

Symptoms

The upper leaf surface develops red, brown or yellow areas and the underside produces bright yellow to orange spores that correspond to the patches above.  Infested leaves become brown in patches, fall prematurely and flower and fruit may also be infected.  This overall, results in a loss of vigour and in small plants may lead to death.  

 

Pelargonium x hortorum

 

Myrtle Rust (Puccinia psidii) This fungal disease infects plants in the Myrtaceae family and was only recently detected in 2010 and has since spread across eastern Australia from the Northern Territory to Queensland, NSW, Victoria and Tasmania. This rust attacks soft and actively growing foliage or shoots with varying symptoms. It normally starts as small purple spots on the leaves from which spores form in yellow pustules that fade to grey as the infection matures and can merge creating leaf distortion and death of the plant. 

The life cycle starts when the powdery yellow spores are distributed by wind to other plants where they germinate and start to grow by piercing the plant cells to obtain nutrients. Germination occurs in dark moist positions with a temperature between 15° to 25°C and the new pustules can release spores in 10 to 12 days, (spores remain viable for 3-months). The spores spread rapidly by wind, water, insects or animals. They are also distributed by plant material, clothing, shoes and vehicles.

 

 Puccinia psidii

 

 

Needle Rust (Melampsora farlowii) infects the new leaves turning them to yellow and fall from the shoot giving the branch a scorched appearance. The fruiting bodies are found on the underside of the leaf and is waxy-red.

 

 

Rust in Poplar (Melampsora species). A fungal problem involving at least two species (Melampsora medusae) and (Melampsora larici-idaei).

The upper leaf surface becomes flecked with yellow to light green and the underside produces bright yellow orange spores that correspond to the patches above.  Infested leaves become brown in patches, fall prematurely and shoots may die back as a result of not being hardened off to the elements.  This overall, results in a loss of vigour and in small plants may lead to death.  

The source of the fungus is from other infected plants or fallen leaves and is dispersed by wind.

Host plants include Lombardy Poplars particularly Populus nigra 'Italica' and cottonwoods.

 

 

White Rust (Albugo candida) forms snow white pustules that contain colourless spores that turn yellow then brown and are found on the underside of leaves.

 

White Pine Blister Rust (WPBR) is caused by the fungus (Cronartium ribicola). It is a obligate parasite requiring a living host to survive. The life cycle requires two host species with part of it life on the Pinus species and the other part on Ribes species. First cankers or sores appear on the Pinus species realising spores that land on the Ribes species infecting it. The infection produces a different type of spore that land on the needles and growing branches of the Pinus species and eventually forming cankers. The spores are spread by wind and prefer cool moist conditions. Symptoms include brown spots on the needles and the appearance of dead branches in the crown. Cankers will also appear on the trunk and it tends to attack young trees. Control methods include removal of Ribus species in the affected areas and breading naturally resistant Pinus species.

 

The Rust (Endophyllum sempervivi) affects Sempervivum species by infecting the young leaves and eventually the crown. The mycelium then travels to the roots and extends into any off shots. Leaves that are infected turn yellowish, grow longer and are thin. Persistent infection may kill the plant.

 

Source and Dispersal

The source of the fungus is from other infected plants or fallen leaves that contain the fruiting bodies and is dispersed by wind.

 

Favoured Conditions

Generally rust is more prevalent during summer, preferring warm humid conditions and particularly when the leaves are damp.

 

Affected Plants

A wide range of ornamental annuals, perennials, ferns, trees, shrubs including, Hibiscus species that are infected by Kuehneola malvicola predominantly in southern USA.

 

Abies species are infected by many types of rust including (Milesia fructuosa) and (Uredinopsis mirabilis).

 

Abutilon, Phymosia and Alcea species are infected by the rust (Puccinia heterospora).

 

Alnus species are occasionally infected with Leaf Rust (Melampsoridium hiratsukanum) which forms yellowish pustules on the leaves that develop turning the leaf brown.

 

Amelanchler species and Calocedrus decurrens are infected by several rust species including (Gymnosporangium libocedri).

 

Antirrhinum majus (Snapdragon) is infected by the rust (Puccinia antirrhini). This fungal problem that infects the epidermal layer on the leaf underside, forming pale green areas that are raised and split open revealing reddish brown spores that have a dusty appearance.  

As the infestation grows, concentric rings of spore pustules appear around the original infection.  The corresponding position on the upper leafs surface turns yellow eventually causing the leaf to wilt and die.  The infestation is not restricted to the leaves; all above ground parts of the plant are susceptible and infected plants transmit the fungus dispersing it by wind.

Infected plants should be removed and destroyed.

 

Anemone and Prunus species are infected by the rust (Tranzschelia pruni-spinosae) that stimulates abnormal growth in the plant during spring.

 

Aquilegia, Anemone, Delphinium and Clematis species are infected by the Rust (Puccinia rubigo-vera var. agropyri).

 

Arctostaphylos manzanita is infected by the rust (Pucciniastrum sparsum) occurring in coastal regions but is not normally detrimental to the plant.

 

Artemisia species are infected by the rust (Uromyces ari-triphylli) which is a systemic disease that is transmitted through seeds. It causes the leaves to turn yellow then die and can infect all parts of the plant except the roots.

 

Bambusa species are infected by the rust (Dasturella divina) which forms elongated brownish strips on the leaves.

 

Berberis species may be infected by the Rust (Puccinia graminis) that forms orange spotting on the leaves. It certain regions plants infected with this rust must be removed and destroyed to avoid infecting neighbouring agriculture crops.

 

Betula species may be infected by Leaf Rust (Melampsoridium betulinum) that forms reddish-yellow spots on the leaves and heavy infestation can defoliate the tree. The host tree changes to Pseudolarix species during the sexual stage and causes blistering of the leaves.

 

Calendula species may be infected by the Rust (Puccinia flaveriae).

 

Callistephus and Solidago species may be infected by the Rust (Coleosporium solidaginis) which forms bright yellow spots particularly on new foliage or young plants.

 

Canna species may be infected by the rust (Puccinia Thaliae).

 

                  Canna indica

 

Centaurea species are infected by the rust (Puccinia cyani) and (Puccinia irrequisita) which can cover the stems and leaves.

 

Cleome species are infected by the rust (Puccinia aristidae) but rarely requires control.

 

Dianthus species are infected by the rust (Uromyces dianthi) which forms powdery brown spots that appear on both sides of the leaves. The leaves curl and die and the plant becomes stunted. This is a common problem that occurs when grown in a protected enclosure (hot house).

 

Ficus species are infected by the rust (Cerotelium fici) which forms small brown spots, and causes the leaves to turn yellow then fall prematurely.

 

Fuchsia species are infected with (Pucciniastrum epilobii). This fungus caused purplish red blotches on the upper leaf surface, that become dry in the middle and result in a brown patch with purple edges.  On the underside of the leaf, corresponding to the patches, yellow orange spores form.  Heavily infected leaves become yellow and drop prematurely.  This leads to a loss of vigour in the plant and infected plants transmit the fungus.  

Certain cultivars are more susceptible than others, particularly 'Orange Drops' and 'Novella'.

 

Hydrangea species is infected by (Pucciniastrum hydrangeae) causing yellowish brown pustules to appear on both sides of the leaf. The leaf becomes dry and brittle.  

 

                  Iris species

 

Iris  and Dietes species are very susceptible to the rust (Puccinia iridis). Leaves form rusty red powdery spots that enlarge. They are appear on both sides of the leaves causing the surrounding area to turn pale yellow then brown and the black spores appear soon after, overwintering on dead infected leaves. Plants may be heavily infected but normally survive attack.

 

Larix species are infected by several Needle Rusts including (Melampsora paradoxa), (Melampsora medusae) and (Melampsoridium betulinum). The fungi attacks the needles predominantly towards the branch tips turning them yellow and eventually killing them . The underside of the leaf develops pale yellow fruiting bodies.

 

Lupinus species are infected by three species of rust including (Puccinia andropogonis var onobrychidis).

 

Malus andChaenomeles species may be infected by the rust (Gymnosporangium juniperi-virginianae) or (Gymnosporangium clavipes) which forms brown or bright orange spots on the leaves or twigs and can defoliate the tree. Juniperus virginiana and Mespilus germanica may also be infected by rust.

 

Mathiola and Arabis species are infected by White Rust.

 

Pinus species are infects by the Comandra Blister-rust (Cronartium comandre).

 

    

Plumeria rubra                           Leaf upper surface                    Leaf underside

 

Plumeria species are susceptible to the rust (Coleosporium plumeriae). Leaves and flowers may be infected with the underside forming bright yellow pustules and causes premature leaf or flower drop.

 

Populus nigra 'Italica' is infected by the rust (Melampsora species) which forms pustules to form on the leaves turning them brown and causing premature leaf drop.

 

Rhododendron and Tsuga species are infected by the rust (Pucciniastrum vaccinii) and is commonly found in nursery stock, spreading rapidly. Tsuga species are also infected by Needle Rust.

 

Ribes species are infected by the rust (Cronartium ribicola). This leaf rust appears on the underside of the leaves (preferably older leaves) forming dusty brown pustules and is a serious problem. This rust only appears when White Pine (Pinus strobes) grows near where the alternate stage of the fungus occurs.

 

Rudbeckia species are infected by several species of rust including (Puccinia dioicae) and (Uromyces rudbeckiae).

 

Salix species are infected by four types of (Melampsora species).

 

Senecio, Bellis and Calendula species are infected by the rust (Puccinia lagenophora) which forms blister-like pustules that release brown spores.

 

Sorbus aucuparia is affected by several rust from the (Gymnosporangium species) causing circular yellow spots, that appear on the leaves during summer and develop into orange cup-shaped fruiting bodies.

 

Trillium species are infected by the rust (Uromyces halstedii) that damages the leaf surface.

 

Festuca arundinacea      Rust

 

Turf Grass are susceptible to rust (Puccinia species) and (Uromyces species), causing yellow flecks to appear on the stems and leaves. These markings enlarge before the pustules form and in severs cases the lawn has a yellow, red or brown appearance.

The infection appears from spring to summer under humid low light conditions and turf that is under stress or with excessive nitrogen in the soil is more susceptible. Many species may be infected including Lolium perenne (Perennial Ryegrass) and Poa pratensis (Kentucky Bluegrass).

 

                  Rust on Perennial Ryegrass

 

Viburnum species are mildly affected by two types of rust (Coleosporium viburni) and (Puccinia linkii).

 

Viola species are infected by the rust (Puccinia violae) which forms green spots on the underside of the leaves. It is not commonly seen on cultivated plants.

 

Non-chemical Control

Cut off and destroy any infected branches, fallen leaves and remove heavily infected plants. Improve the culture by, pruning to improve air circulation, allow space between plants and avoid over crowding.  Avoid planting susceptible species.  Plants that are infected with a systemic form should be removed and destroyed

 

Chemical Control

Not possible to spray large trees but young plants may be treated with a protectant fungicide such as wettable sulphur. In a domestic garden small plants such as Fuchsia species may be sprayed with a protectant chemicals as symptoms appear, aided by the removal of existing infected leaves.  Under commercial conditions stock may be sprayed with a fungicide such as oxycarboxin.

Note

Always read the label for registration details and direction of use prior to application of any chemicals.

DISEASE

   NAME

     Twig Blight

     Phomopsis juniperovora

Description

Phomopsis Twig Blight of Juniper is a fungus problem commonly known as cedar, juniper, or needle blight and is normally a leaf or shoot infection commonly found in young plants and on the new growth of older plants.

Symptoms

The tips of young needles form yellow spots and as the infection progresses from the needle to the stem the infected area turns red brown to ash grey associated with dieback. If allowed to continue the entire branch dies as the fungus mycelium progresses into the main stem. It grows rapidly along the inner bark, killing the cambium and turning the wood brown.

Liquidambar species

Lesions occur on the stems; these frequently develop into cankers at the point of healthy and diseased tissue. The canker can girdle the branch of young plants, but older plants are more resistant. Young or small plants may be completely covered in the fungus turning the plant brown.

Only immature needles are affected and when the needled turn deep dark green they are not susceptible to the disease. As the infection matures small black spots or fruiting bodies may be seen using a magnifying glass on the dries grey areas.

Source and Dispersal

The fungal spores (conidia) are dispersed by wind, insects and from infected plants or parts of plants that are trimmed from the tree. It is also dispersed by splashing water or contaminated stock. Overhead irrigation especially in nurseries is conducive to infection. The fungus will not die if the host becomes dry but will continue growing when moisture returns.

Favoured Conditions

The fungus prefers cool humid climates or 15 ° to 27 ° C (60 ° to 82° F) and is not commonly seen in warm coastal regions and may continue living in dead wood, leaf litter or harvested fruit for up to two years.

Affected Plants

Many plants are affected by this fungus such as (Thuja), species of true cedar (Cupressus), and false cedar (Chamaecyparis), European larch (Larix decidua), jack pine (Pinus banksiana), English yew (Taxus baccata), Japanese plum yew (Cephalotaxus drupacea), Douglas fir (Pseudotsuga taxifolia), species of fir (Abies), and Cryptomeria japonica

Note

Listed below are other Twig Blights generally specific to there host.

Abies species are infected by Needle and Twig Blight (Rehmiellopsis balsameae), turning the current season's needle growth reddish before dieing.

Cedrus species are infected by the Tip Blight (Diplodia pinea) that forms cankers in branchlets causing die back.

Cercidiphyllum japonicum is susceptible to the twig blight (Phomopsis species), causing disfigurement of the branches.

Cordyline species are infected by the Tip Blight (Physalospora dracaenae) that turns the leaves light brown and dry from the tips down, affecting the lower ones first.

Cornus species are susceptible to three types of Twig Blight (Myxosporium everhartii), (Cryptostictis species) and (Sphaeropsis species). These fungi form cankers or blighting on the twigs.

Euonymus species are suseptable to Phomopsis Dieback (Phomopsis species). This causes the twigs and small branches to die back and mild cases are not normally detrimental to the plants growth.

Laburnum anagyroides is infected by the Twig Blight (Fusarium lateritium) causing brown lesions to appear in the twigs and progressing to blight the leaves appearing as wet areas.

Ligustrum species are susceptible to the Nodular Gall (Phomopsis species). This fungus causes small 25mm wide galls to appear on the plant. The fungus normally gains access through moist damaged tissue.

Liquidambar species are infected by the Twig Blight (Phomopsis juniperovora) causing cankers along the stems.

Magnolia species are susceptible to the Dieback (Phomopsis species). In these trees cankers form longitudinal cracks turning the bark dark brown and the heart wood blue-grey. Currently there is no known control and heavily affected plants should be removed.

Pinus species are infected by Cenangium Twig-Blight (Cenangium abietis) attacking the current season growth.

Salix species are infected by the twig blight (Physalospora miyabeana) that forms brown spots on the leaf upper surface and whitish lesions appear on the twigs.

Sequoia species are infected by Needle Blight (Chloroscypha chloramela) which attacks the young growth.

Taxodium distichum is infected by the Twig Blight (Pestalotia funereal)  that forms small spots on the leaves, cones and bark, normally during wet periods.

Non-chemical Control

Avoid watering plants from above or wetting the foliage especially in the late afternoon. When planting allow space between each plant for good air circulation.

Remove affected foliage or wood by pruning and dispose off site. In a nursery avoid having seedlings placed alongside older stock or using Junipers as a windbreak around the nursery. When planting susceptible plants avoid poorly drained soils.

Chemical Control

Regular spraying where possible during the periods that are favourable for fungus development. Fungicides include;

Systemic types, Biteranol, carbendazim, triforine

Protectants; chlorothalonil, copper oxychloride, mancozeb, thiram, zineb

Note

Always read the label for registration details and direction of use prior to application of any chemicals.

DISEASE

   NAME

     Armillaria Root Rot, Honey Fungi

     Armillaria luteobubalina

  

Description

This naturally occurring fungus grows between the bark and wood of trees producing distinctive cream sheets of hyphae. The toadstool-like fruiting bodies are yellowish brown and appear from the soil or sprout out of the base of the host plant.

Image by Dr Brett Summerell

Symptoms

This is a vigorous fungus that attacks the roots of trees and is not normally noticed until dieback starts to occur. Affected plants generally appear declined, with some dieback and by this stage; the disease may be well established. Leaves can turn yellow, shrivel and fall from the plant and the branches die back. Citrus trees may produce a heavy crop of fruit just before death. Splits often occur on the trunk of affected trees and the bark may lift revealing white sheets of mycelium or hyphae under the bark. These hyphae will have a distinctive "mushroom" smell. Affected roots become spongy, powdery or jelly-like and when dissected reveal similar white sheaths under the bark. Infected plants may survive for many years before final death of the tree.

                 

Image by Dr Brett Summerell

Source and Dispersal

This fungus is a native species that is naturally found in Eucalyptus forests and woodlands throughout eastern Australia and south-western Australia. It is commonly found on old tree trunks and decaying wood where honey coloured toadstools appear from the base of the host or surrounding soil in May-June. The toadstools produce white spores that are dispersed by wind, but generally the fungus spreads underground through contact between infected and uninfected roots. The fungus can grow about 1-1.5 metres per year along a root. This species, unlike those in the northern hemisphere does not produce rhizomorphs, thick strands that are flat resembling shoe-strings.

Mycelium on wood     

Image by Dr Brett Summerell

The fungus is not spread by contaminated soil as it only grows in root material. Spread to new sites is either through spore movement (very rare), movement of infected plants or through movement of contaminated wood chip used for mulch. Dead or dying trees should be inspected for the presence of this pathogen prior to use as mulch.

This fungus can survive for many years in infested root and stem material depending on the size of the material and speed of decomposition of the wood.

Favoured Conditions

This fungus prefers sandy soil types and is more frequently found in more freely drained soils. Moisture is required for growth of the fungus along the root system. Generally the damage caused to plants is greater on plants that are already under stress or weakened. The retention of infested root systems and stumps in the soil has contributed to an increase in the occurrence of this disease.

Affected Plants

The host range for this fungus is extremely wide and includes many ornamentals and Australian native plants. Fruit trees and perennials are also commonly attacked. The most susceptible species include oaks, camellias, azaleas, roses and eucalypts.

Amaryllis, Narcissus and Hippeastrum species are also infected.

Cedrus species trunk     

Image by Dr Brett Summerell

Cedrus species are also affected by Armillaria root rot causing the roots to rot and the trunk to swell and spilt open. There is no control for these infections.

Non-chemical Control

Control of this disease is totally dependent on removal of the inoculum of the fungus from the soil. To be effective this will require removal of the infested roots and stem, a process that may be difficult in garden beds. Infected plants should be removed and disposed of, but it is not necessary to remove the surrounding soil as the fungus only occurs in the plant.  When clearing affected land for cultivation, remove all stumps and roots and allow 2 to 3 years prior to replanting.

Trees that are in the early stages of attack may be saved by removal of the affected roots and leaving remaining roots exposed for several years. Top soil around the trunk should also be removed for a distance of up to 1m and affected trees should be fertilised and watered to encourage vigour.

Chemical Control

There is no practical or effective chemical control. Fumigation has been carried out to eradicate the fungus but success is dependent on the removal of large sources of inoculum. However many of the chemicals used for this purpose are highly toxic and have restricted usage now.

Note

Always read the label for registration details and direction of use prior to application of any chemicals.

Amendments by

Dr Brett Summerell
Director Science and Public Programs
Royal Botanic Gardens Trust, Sydney

DISEASE

   NAME

     Phytophthora Rot

     Phytophthora species

Pathogen Name

A number of Phytophthora species cause these diseases but the most important species in Australia is the cinnamon fungus, Phytophthora cinnamomi. This species is exotic to Australia and probably originated from south east Asia; it has probably been present in Australia for close to 200 years. Phytophthora are fungal-like organisms that are related to some protozoa and algae; they are microscopic and cannot be observed by the naked eye.

Description

There are many types of Phytophthora Rot but generally the disease affects the plant by causing a soft rot of the affected plant part. The most common form of the disease is a rotting of the roots that occurs below ground with no visible symptoms of the disease above ground until the disease starts to cause leaf drop.

Symptoms

The disease is initiated below ground in the soil, usually on the feeder roots of a plant. The pathogen grows through the roots killing cells and eventually causing an extensive root decay. This causes the infected plant to lose vigour and the leaves to yellow and die. Entire branches starting from the top then die, quickly during hot weather or linger for months. The infection occurs on the root hairs causing small and large roots to rot.  The symptoms of the disease are often very difficult to differentiate from drought symptoms, mainly because the affected root system prevents the uptake of moisture from the soil. Once the disease has progressed far enough large branches will die causing the typical dieback symptoms.

  

                 

There are a number of other diseases caused by Phytophthora species

Twig Die Back (Phytophthora ilicis) attacks Ilex species causing black leaf spots and black stem cankers.

Phytophthora cactorum is known by several common names depending on which plant is being attacked and they have various symptoms. Plant species are listed below.

Root Rot (Phytophthora richardiae) infects Zantedeschia species causing the leaves to turn yellow, wilt and die. Flowers are deformed if they bloom and the infection can also be seen in the new growth, eventually killing the plant. On inspection the roots show signs of decay.

Stem Rot (Phytophthora cryptogea) infects the roots and stems turning them brown and seeds are also attacked causing decay. It is commonly found on Tagetes erecta and infected plants wilt, collapse and die.

Source and Dispersal

Sporangia     Zoospores    

Image by Dr Brett Summerell

Phytophthora species produce sporangia that contain specialised zoospores that have flagella that allow them to move through the soil moisture small distances. These spores encyst on the root and then penetrate the root. The pathogen also produces chlamydospores, specialised survival spores that allow it to survive in the soil for extended periods of time. The chlamydospores can be transported in soil, even extremely small amounts, allowing the pathogen to be dispersed very easily throughout an area and from one location to another. The zoospores are easily moved in water flowing through soil and so are easily dispersed down slopes. It is not uncommon for the disease to move in fronts down a slope.

                  Chlamydospores, specialised survival spores

Image by Dr Brett Summerell

Favoured Conditions

Phytophthora root rot is favoured by poorly drained soils or in soils that are waterlogged for short periods of time. The disease generally occurs during periods when the temperature is above 16ºC although it has been observed in snow gum country in the Barrington Tops National Park and in southern Tasmania. It also prefers soils that have little organic material.

        

Affected Plants

                  Xanthorrhoea species

Image by Dr Brett Summerell

The host range that is attacked by Phytophthora cinnamomi is enormous and is still not well understood but includes many Australian native plants, Rhododendrons, Acer  and Prunus species, conifers, cabbage tree and strawberries. Some Australian plant families that are quite susceptible include species in the Proteaceae, Epacridaceae and Xanthorrhoea species.

Alphitonia excelsa

Alphitonia excelsa can be infected by Phytophthora cinnamomi causing loss of foliage, death of the upper branches and cankers on the trunk.

Cactus such as Cereus species may be infected with Slimy Collar Rot (Phytophthora cactorum) which forms a soft black area at the base of the plant that is water soaked.

Chamaecyparis species may be infected with the Root Rot (Phytophthora lateralis) that attacks roots, trunk, stems and leaves.

Cornus species are infected by Crown Canker (Phytophthora cactorum) and in this case the tree is partially infected initially with one side producing smaller leaves that turn reddish in late summer. The leaves may also shrivel and die prematurely, during dry periods and small and large branches die. After a couple of seasons the tree becomes completely infected with poor top growth and an inconspicuous canker develops at the base of the trunk. Eventually the tree dies.

Erica species are infected by (Phytophthora cinnamomi). The symptoms include foliage turning greyish towards the top, and then the plant wilts then dies with evidence of infection at the base.

Phytophthora in Eucalyptus species
Image by B. Sonsie



Image by Dr Brett Summerell

Eucalyptus species are infected by Phytophthora cinnamomi causing rapid die back of the tree with blackened trunk loss or upper growth and is a serious problem for certain species such as Eucalyptus diversicolor (Karri).

Euphorbia pulcherrima is susceptible to Root Rot (Phytophthora and Pythium species). Roots become dark and the rot can extend up the stem. The plant is also susceptible to leaf blight resulting from the same fungal disease.

Hedera species are infected by Phytophthora Blight (Phytophthora palmivora). This fungus causes leaf spots, foliage blight and stem rot.

Palms such as Archontophoenix, Caryota, Chamaedorea, Cocos, Dypsis, Howea, Liculia, Linospadix, Livistona, Phoenix, Ptychosperma, Rhapis, Roystonea, Syagrus, Washingtonia and Wodyetia species are also susceptible to Phytophthora Blight forming large irregular areas on the fronds that become dark and rotten and limited by the veins

Lilium species are infected by Foot Rot (Phytophthora cactorum) which attacking the stems just below the soil level causing the plant to topple and if infection occurs as the leaves are emerging the base of the infected leaves which collapse remain attached to the bulb.

Morinda citrifolia is infected by Phytophthora Blight, black flag disease (Phytophthora species) which causes the foliage to turn black and limp. The fruit and stems are also infected causing them to turn brown-black and whither.

                  Morinda citrifolia

Orchids such as Cattleya, Cymbidium, Cypripedium, Dendrobium, Epidendrum, Paphiopedilum, Phalaenopsis and Zygopetalum species are infected by Black Rot (Phytophthora or Pythium species). This causes the leaves, pseudobulbs, rhizomes and roots to form a dark soft rot, normally occurring towards the base of the plant.

Saintpaulia, Dianthus, Gypsophila, Limonium and Anemone species are infected by Root and Crown Rot (Phytophthora nicotianae). This is a fast moving fungus that turns the roots blackish then extends to the crown and petioles causing wet rot of the crown then wilting, eventually killing the plant. When found as Phytophthora Leaf Spot or Blight, angular spots appear with water-soaked margins as in Cordyline and Philodendron species.

Sedum species can be infected by up to three Stem Rot fungi including (Colletotrichum species), (Phytophthora species) and (Pellicularia filamentosa). Commonly occurring in wet soils.

Ulmus and Acer species are also infected by (Phytophthora cactorum) and this is known as Bleeding Canker. This casual disease initially causes cankers in the bark that ooze sap and the sapwood forms reddish lesions with greenish margins. The leaves on affected branches turn yellow, wilt then die and mildly affected trees may survive.

Many species are infected by the Bleeding Canker including Acer platanoides, Acer rubrum, Acer pseudoplatanus, Acer saccharinum, Betula species, Liquidambar styraciflua, Aesculus x carnea, Tilia, Salix and Quercus species.

Non-chemical Control

The most effective control for all Phytophthora diseases is prevention primarily because it is extremely difficult to control Phytophthora diseases after they are established in the plant. As Phytophthora species are most easily transported in infested soil quarantine is an essential component of control of the disease and it is for this reason many areas have hygiene protocols to stop the pathogen being introduced into an area.  It is recommended that bush walkers take care not to introduce the pathogen on their boots into un-infested areas and for this reason it is suggested that walking boots be cleaned and preferably sterilised (with 70% methylated spirits) prior to starting a walk.

Cultural techniques such as cultivating the soil regularly with added animal manure and other organic substrates to ensure there is good drainage will also help to minimise the impact of the disease. The plants can be mulched with straw or other organic material taking care that the base of the trunk is left clear. Avoid over watering the soil and observe hygiene in regards to tools, containers or shoes to reduce spreading the infection.

Potting mixes should be pasteurised for 30min at 60ºC to ensure that they are free of the pathogen. It is also very important to grow pots off the ground to prevent the splash of infested mix or water from an infected plant to clean plants.

.

Avoid damaging the bark particularly at ground level and seal any wounds that occur. If cactus or tree species are infected it is possible to cut out the infected area when first seen in order to contain it. Correct tree surgery techniques are required for large trees.

Chemical Control

There are a number of fungicides that are registered for use in the control of these diseases. The most effective chemical control are based on the use of chemicals containing potassium phosphonate. This chemical effectively enhances the defence systems of the plant and has been shown to be most effective in controlling Phytophthora diseases. It is essential that the chemical be applied when the plants is exporting nutrients to the roots, so this is best in the warmer months. The chemical can be applied as a stem injection or a foliar spray, and in some situations as a soil drench.  There are specialised stem injecting equipment available for stem injections on larger trees.

Image by Dr Brett Summerell

Note

Always read the label for registration details and direction of use prior to application of any chemicals.

Amendments by

Dr Brett Summerell
Director Science and Public Programs
Royal Botanic Gardens Trust, Sydney