Fraxinus excelsior

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

     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

     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.

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

     Leaf Spot (General)

     Various Leaf Spot Species

Description

There is a wide variety of fungal leaf spots that infect perennials, shrub and trees. Some are specific to the host while others can affect a range of plants.

Symptoms

Generally light brown to purplish or blackish spots appear on the leaf and form concentric rings of fruiting bodies. The spots may leave holes, perforating the leaf or expand with pale green to yellowish margins and when the holes merge the leaf normally dies. There are many different types of leaf spot, some are discussed below.

Alocasia species     

Alternaria Leaf Spot (Alternaria nelumbii) forms a small reddish brown spots that are boarded in light green, and as they develop in size the leaf curls and dies from the margin inwards. Normally occurs on Nelumbo species (water lilies).

Helminthosporium Disease

Helminthosporium Disease (Bipolris species), (Drechslera species) and (Exserophilum species) are responsible for several leaf spots that occur on all Turf Grass species. Generally they form black or white spots that may be faded and produce masses of spores in the thatch during late summer, under humid conditions. The life cycle is short and when conditions are favourable spores are splashed onto the foliage from the thatch, causing wide spread infection. Cynodon dactylon (common couch) is most susceptible and found in bowling or golf greens where it is a serious problem.

Banana Leaf Spot     

Banana Leaf Spot (Mycosphaerella musicola) is found on many species of banana causing pale yellow streaks on the young leaves to turn brown with dark spots. The leaf then becomes dried, brown and dead commencing from the margins, eventually the leaf dies. Control requires removal of infected foliage or the spraying of a fungicide and fungicides should not be used during the fruiting period.

                  Lophostemon confertus (Brush Box)

Leaf Spot on Brush Box (Elsinoe species). This is a casual fungus that attacks the epidermal layer of the leaf, forming circular spots that are up to 25mm across and are often restricted by the main vein.  These spots are a dull yellowish brown but can also have purplish patterns.  A leaf may have more than one spot develop on its surface and normally appears on scattered leaves throughout the tree.  This doesn't affect the vigour of Lophostemon confertus.

Palm Leaf-scab (Graphiola phoeicis) appears as yellow spots and develop into scabs or warts that are outwards hard and dark but with a soft centre with powdery yellowish brown spores. The infected leaves eventually die.

Palm Leaf Spot, Chamaedorea elegans

Palm Leaf Spot (Pestaloptiopsis species) appears as a small spot with a dark centre on the leaves and affects palms that are growing in shaded humid positions and normally control is not required, though infected fronds should be removed.

Source and Dispersal

Infection source is other contaminated plants and the spores are spread by wind or by splashing water.  The fruiting bodies are black spots that appear on the damaged tissue releasing spores.

Favoured Conditions

This fungus prefers a warm humid environment and leafy plants with soft new growth, particularly if they are crowded.

        

Affected Plants

There are many ornamental and native plants that are hosts to a wide range of fungal leaf spots. Some specific ones are listed below. Plants such as Cornus or Paeonia species are infected by a large variety of leaf spots, while other plants attract a specific leaf spot.

Generally a healthy plant can tolerate fungal leaf spot attack, though it may make the plant look unsightly. In trees and shrubs it is difficult to control and generally not necessary, but in perennials and annuals control may be necessary in order to save the plant.

Acalypha and Arctotis species are infected by up to three leaf spots including (Cercospora acalyphae) and (Ramularia acalyphae) that rarely require control.

Acer species are infected by Purple Eye (Phyllosticta minima) which forms spots with brownish centres and purplish margins causing the death of the leaves.

Acer species are also infected by Tar Spot (Rhytisma acerinum) which forms round black spots that have yellow margins. Not normally seen on cultivated trees, but seen in forests.

Adiantum, Asplenium, Blechnum, Cyathea, Davallia, Nephrolepis, Platycerium, Polypodium and Pteris species are infected by the leaf spot (Pseudocercopora species) which forms circular brown spots on the fronds and heavy infection can defoliate a plant.

Aesculus species are occasionally infected with the leaf spot (Septoria hippocastani) which forms small brown spots.

Agave species are susceptible to the leaf spot (Coniothyrium concentricum), which appear as greyish spots up to 20mm (1in) across with concentric rings and black fruiting bodies. Affected leaves are destroyed as the infection spreads.

Albizia julibrissin is susceptible to the fungal leaf spot (gloeosporium aletridis), which does not normally require control.

Amelanchler, Chaenomeles, Crataegus and Rhaphiolepis species Mespilus germanica are infected by the leaf spot (Fabraea maculata) which may cause considerable damage during wet periods.

Aquilegia species can be infected by three types of Leaf Spot including (Ascochyta aquilegiae), (Cercospora aquilegiae) and (Septoria aquilegiae), normally appearing during humid conditions forming spots on the leaves.

Arbutus species are infected by two leaf spots (Septoria Unedonis) which produces small brown spots on the leaves and (Elsinoe mattirolianum).

Arctostaphylos manzanita is infected by the leave spot (Cryptostictis arbuti) which damages leaves but is not normally detrimental to the shrub.

Aspidistra species are infected by the leaf spot (Colletotrichum omnivorum) causing whitish spots on the leaves and petiole.

Aster species are infected by many leaf spots including (Alternaria species), (Cercosporella cana), ( Ovularia asteris) and (Septoria asteris).

Aucuba species are infected by several leaf spots, usually as a secondary infection after aphid attack. These include (Phyllosticta aucubae) and (Phyllostica aucubae).

                     Azalea

Azalea (Rhododendron species) are susceptible to Leaf Scorch (Septoria azalea). This fungal disease forms reddish- brown spots which expand and engulf the leaf, with fruiting bodies appearing in the centre. Infected leaves die, then fall and the branchlets wilt. This problem is more serious during wet periods and may require control using a fungicide.

Banksia robur

Banksia species are infected by several leaf spots causing chlorotic areas that have brown centres and is not normally a major problem for the plant.

Betula species may be infected by the Leaf Spots (Gloeosporium betularum) that forms brown spots with darker margins and (Cylindrosporium betulae) that also forms brown spots with faded indefinite margins.

Bougainvillea species are infected by the leaf spot (Cercosporidium bougainvilleae) which forms rounded spots with dark margins that yellowish ting. Infected leaves die and fall from the plant.

Calendula species are infected by the Leaf Spot (Cercospora calendulae) which rapidly infects the plant spotting the leaves and killing the plant.

Callicarpa species may be infected by the leaf spot (Atractilina callicarpae) forming irregular brownish spot or (Cercospora callicarpae) which can defoliate the plant in subtropical climates.

Campsis species may be infected by several fungal leaf spots including (Phyllosticta tecomae), (Septoria tecomae) and (Cercospora duplicata).

Carpinus species are infected by the leaf spots (Gloeosporium robergei), (Gnomoniella fimbriata) and (Septoria carpinea), all are minor infections not normally requiring control.

Carya species are infected by several leaf spots including (Gnomonia caryae) that infects leaves with irregular reddish spots on the upper surface with corresponding brown spore producing spots on the underside. It also has a secondary spore release that occurs on the dead leaves where it over winters. Other leaf spots include (monochaetia desmazierii) and (Marssonina juglandis).

Ceanothus species are susceptible to the leaf spot (Cercospora ceanothi) and (Phyllosticta ceanothi) both are of minor importance not requiring control.

Celtis species are infected by many leaf spots including (Cercosporella celtidis), (Cylindrosporium celtidis), (Phleospora celtidis) and (Septogloeum celtidis).

Chrysanthemums species are infected by the leaf spot (Septoria species) which forms yellow spots appear toward the edge of the leaves; these become enlarged brownish patches with yellow margins.  Damaged areas may converge and in severe attacks and the leaves may fall prematurely or flower production is reduced.

Clematis species are infected by the fungal disease (Ascochyta clematidina) which may cause stem rot or leaf spots that are water soaked areas with reddish margins. The infection spreads from the leaves to the stem causing wilting and eventually girdling the stem killing the plant. There are many fungal leaf spots that infect this plant including (Cercospora rubigo) and (Septoria clematidis)

Dracaena deremensis

Cordyline and Dracaena species may be infected by the leaf spot (Phyllosticta maculicola) which forms small brownish spots that have yellowish margins and has black fruiting bodies that forms coils of spores. These plants are also susceptible to other leaf spots such as (Glomerella cincta) and (Phyllosticta dracaaaenae). Keep foliage dry to avoid infection.

Cynodon dactylon,  Pennisetum clandestinum and many other Turf Grasses are susceptible to Helminthosporium Disease.

Daphne species are infected by the leaf spot (Gloeosporium mezerei) and (Marssonina daphnes) both of which form thickish brown spots that are seen on both sides of the leaves. Infected leaves turn yellowish before dieing.

Dendranthema species are infected by many leaf spots such as (Septoria chrysanthemi) which first forms yellowish spots up to 25mm (1in) across that become black. Infected leaves die prematurely and persist on the plant.

Dianthus species may be infected by the leaf spot (Septoria dianthi). It forms light brown rounded spots that have a purplish border. The scattered spots on the lower leaves can also be found on the stems and the spores are dispersed by water from the tiny black fruiting bodies.

Dieffenbachia species are infected by several leaf spot fungi including (Cephalosporium species) and (Myrothecium species).

Eucalyptus species

Eucalyptus species are infected by many fungal leaf spots such as (Mycosphaeralla species), (Hendersonia species) and (Monocheatia monochaeta). Generally leaf spots appear on the juvenile or new leaves causing brownish spots that enlarge and may have a purplish halo around the margin.  Mature adult leaves are not normally infected and the trees rarely require control measures.

Fern species are infected by the leaf spot, (Alternaria polypodii). This fungus appears as brown circular or oblong spots that congregate along the margins of the pinnae causing the fronds to turn brown and die.  It is spread by wind currents from plant to plant and control methods include removing infected fronds and maintaining a drier atmosphere.

Ficus species are infected by various fungal leaf spot including (Pseudocercospora species). Generally the fungal attack forms circular or irregular dark coloured spots on the leaves eventually causing them to fall prematurely.

Ficus elastica is susceptible to many fungal leaf spots including (Alternaria species), (Leptostromella elastica) and (Phyllosticta roberti).

                    Strawberry

Fragaria x ananassa (Strawberry) is infected by the fungal leaf spot (Mycospharella fragariae). The mature leaf is initially infected with well defined brown spots that that turn light grey with red-purplish margins. As the spots merge they form large brown blotches and the leaf turns yellow then dies. This fungal attack normally occurs on plants in poor health and can be a serious problem early in the season seriously damaging stock.

Fraxinus species

Fraxinus species are infected by the leaf spot (Gloeosporium aridum) giving the leaf a scorched appearance as large blotches appear from the margin or apex and turn brown with a papery texture. It is more prevalent during rainy periods and infected leaves fall prematurely. Collect and depose of fallen leaves otherwise control is not normally required.

Fuchsia species may be infected by the leaf spot (Septoria species) or ( Cercospora species), both form spots with dead centres and dark margins.

Gladiolus species are infected by Hard Rot or Leaf Spot (Septoria gladioli). On the corms reddish brown circular water soaked spots become large and sunken. These areas dry out and form obvious margins. The leaves may also have these symptoms but is not commonly seen.

Hemerocallis species are infected by several leaf spots including (Cercospora hemerocallis) and (Heterosporium iridis). These may be in the form of black spots or brownish spots that converge killing the leaf. Infected leaves should be removed and burnt.

Hibiscus species

Hibiscus rosa-sinensis, Hibiscus syriacus and Hibiscus tiliaceus are susceptible to several fungal leaf spots including (Ascochyta abelmoschi), (Cerospora kellermanii) and (Phyllosticta hibiscina). All cause spotting or blotching of the leaf surface; remove and destroy infected parts.

Hydrangea species are infected by four fungal species including (Ascochyta hydrangeae), (Phyllosticta hydrangeae) and (Septoria hydrangeae).

Iris species are infected by several fungal leaf spots including (Alternaria iridicola) and (Macosphaerella species).

Iris species are also infected by the leaf spot (Didymellina macrospore) that forms greyish spots with brown water soaked borders and coalesce on the upper part of the leaf. This casual organism commonly occurs after flowering killing the leaves but will not infect the bulbs. The bulbs become weak over several seasons due to the decreased foliage.

There is also a Bacterial Leaf Spot (Bacterium tardicrescens) that is commonly mistaken as a fungal problem causing translucent spots that coalesce and involve the entire leaf. Normally found on Iris species.

Laburnum anagyroides is infected by the Leaf Spot (Phyllosticta cytisii). The leaf forms light grey spots with no definite margin and mature to brown. The black fruiting bodies appear as dots in the centre of the spot.

Leucanthemum species are infected by the leaf spot (Cerocspora chrysanthemi) and (Septoria leucanthemi).

Magnolia species are susceptible to many species including (Alternaria tenuis), (Mycosphaerella milleri) and (Phyllosticta species). Leaves generally turn brown from the apex or margins turning brown or spots appear on the leaf surface and leaves become yellow before withering and dieing. Normally the make the tree look poorly but have little effect on its growth. Control is not normally required.

Nerium oleander is susceptible to several fungal leaf spots including (Cercospora nerella), (Cercospora repens), (Gloesporium species) and (Phyllosticta nerii). Infected leaves should be removed but generally control is not required.

Nyssa sylvatica is infected by the leaf spot (Mycosphaerella nyssaecola) forming irregular purplish blotches.

Orchids such as Cattleya, Cymbidium, Cypripedium, Dendrobium, Epidendrum, Paphiopedilum, Phalaenopsis and Zygopetalum species are infected by several leaf spots including (Cerospora, Colletotrichum and Phyllosticta species). Normally forming dark or dead, circular or irregular areas on the leaves.

Palms such as Syagrus, Howea, Phoenix, Roystonea and Washingtonia species are infected by Leaf-scab (Graphiola phoeicis).

Palms such as Archontophoenix, Caryota, Chamaedorea, Cocos, Dypsis, Howea, Liculia, Linospadix, Livistona, Phoenix, Ptychosperma, Rhapis, Roystonea, Syagrus, Washingtonia and Wodyetia species are susceptible to several fungal leaf spots including;

(Bipolaris spp.), (Cylindrocladium spp.), (Colletotrichum spp.) and (Pestalotiopsis spp.).

Generally the circular leaf spots are brown and may have a yellow halo such as Palm Ring Spot (Bipolaris incurvata). They vary in size from small to large depending on the species. When a plant is healthy it recovers from attack, but heavy infections can defoliate, causing the collapse of the plant.

Palms are also infected by the Brachybasidium Leaf Spot (Brachybasidium pinangae). This fungus forms angular leaf lesions that produce fruiting bodies on the underside and is commonly found on Archontophoenix species.

                  Archontophoenix cunninghamiana

Passiflora species are infected with many types of leaf spot such as (Alternaria passiflorae).

Phoenix species are susceptible to False Smut (Graphiola phoenicis). This fungus forms yellow leaf spots that become hard with a raised with a blackish scab, which produces masses of powdery spores that are thread-like.

                  Pittosporum species

Pittosporum species are susceptible to the leaf spots (Alternaria tenuissima), (Phyllostica species) and (Cercospora pittospori). Circular or angular dark spots appear on the leaves and are surrounded by necrotic areas that are yellowish. Generally removal of infected leaves is adequate control.

Poa species and other cool season grasses are infected by Winter Fusarium Leaf Disease (Fusarium species), which causes small pale spots that are water soaked to appear on the leaves that turn red-brown. Infected leaves become bleached then wither and die, but the infection will not affect the crown or roots of the plant. It can be identified by pink, cotton-like mycelium and the plant prefers cold wet weather.

Populus species are infected by several fungal leaf spots including (Ciborinia bifrons, Ciborinia confundens), and (Mycosphaerella populicola).

Prunus species are infected by several leaf spots including (Cercospora circumscissa and Septoria ravenelii).

Pseudotsuga menziesii Douglas Fir is infected by the Leaf Cast (Rhabdocline pseudotsugae) Symptoms include the needles becoming yellowish at the apex and extending down the needle and spreading to others during moist spring weather turning them brown. Brownish scorched areas are noticeable on the tree from a distance. Control; is not normally required for mature trees but nursery stock may require spraying with a copper based fungicide.  

Psidium guajava (Guava) is infected by (Glomerella cingulate). This fungus courses spots to appear on leaves and mummifies and blackens immature fruit or rots mature fruit.  This fungus can devastate a guava crop.  

Quercus species are infected by several types of leaf spot including (Cylindrosporium microspilum) and (Marssonina martini). These attacks tend top take place later in the season and normally not detrimental to the tree.

Rhododendron species are infected by a large variety of fungal leaf spots including (Cercospora rhododendri) and (lophodermium melaleucum)

Salix species are infected by several fungal leaf spots including (Ascochyta salicis) and (Septogloeum salicinum).

Senecio species are infected by the fungal leaf spot (Alternaria cinerariae) and (Cercospora species), forming dark rounded or angular spots.

Spiraea species are attacked by the fungal leaf spot (Cylindrosporium filipendulae).

Stenotaphrum secundatum (Buffalo) turf grass is susceptible to Grey Leaf Spot (Pyricularia grisea) in domestic and commercial situations devastating lawns. This fungal disease infects the stems and leaves with small brown lesions that enlarge rapidly forming grey-brown spots that have darker borders or surrounded by yellow chlorotic areas. This infection is commonly found on newly laid turf but will also infect established lawns. It is most prevalent during warm humid periods in soil with a high nitrogen level.

Syringa species are attacked by up to six species of leaf spot including (Cercospora lilacis) and (Phyllostica species).

Syzygium species

Syzygium species are infected by fungal leaf spots but normally control is not required.

Tagetes species are infected by the leaf spot (Septoria tageticola), which starts at the base and moves progressively up through the plant, covering the leaves in grey to black spots.

Trillium species are host to several leaf spots, including (Colletotrichum peckii) (Gloeosporium Trillii) (Heterosporium trillii).

Ulmus species are infected by many fungal leaf spots including (Gnomonia ulmea) and (Cercospora sphaeriaeformis).

Veronica species are infected by the leaf spot (Septoria veronicae). The symptoms include small violet to brown spots appear on the upper surface of the leaf and correspondingly yellowish brown on the underside. The spots converge forming a scorched shot-hole appearance and eventually death of the leaf.

Vaccinium ovatum

Vaccinium ovatum is infected by the leaf spot (Rhytisma vaccinii) and (Dothichiza caroliniana).

Vicia species are infected by the leaf spot (Erostrotheca multiformis), which forms greyish spots that enlarge and may defoliate the plant.

Wisteria species are infected by three fungal leaf spots (Phyllostica wisteriae), (Septoria wisteriae) and (Phomatospora wisteriae).

Non-chemical Control

Remove and destroy infected plant material and avoid overhead watering.  When planting select infection resistant varieties. Practice crop rotation and add pot ash to the soil to decrease the plants venerability to the disease. Many species of fungus overwinter in fallen leaves, remove and destroy any litter under the plant.  

Winter Fusarium Leaf Disease in Turf Grasses can be minimised by aerating the soil, reducing thatch and avoid excessive nitrogen in the soil.

Chemical Control

Protective fungicides such as zineb or copper oxychloride should be sprayed at the first sign of infection and cuttings should be sprayed as they start to grow.

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

     Anthracnose (General)

     Various Anthracnose Species

Description

This fungus is a casual organism that attacks leaves, flower, fruit, seed and twigs of the host.

Symptoms

Circular black spots appear primarily on the leaves or fruit but may also occur on the stems and flowers. The spots have a definite margin that may turn purple or black with age. As the spot enlarges the centre dries and may fall out giving the leaf a shot hole appearance or become sunken in some fruit while others form soft blackened areas. Infected leaves turn yellow then fall prematurely and fruit that is infected generally becomes black and rotten as it matures.

There are many variations in the symptoms depending on the type of plant and the species of fungus but generally as the fungal spots merge they form brownish to black dead areas.

Plane Anthracnose (Gnomonia platani) first appears on young leaves and as the leaves mature light brown spots appear along the veins and eventually engulf the entire leaf causing death. The twigs are also infected and often fall to the ground when dead and branches die after cankers appear lower down. This is a serious problem for Platanus occidentalis in North America.

Anthracnose in turf

The Anthracnose (Colletotrichum species) and (Microdochium bolleyi) infects winter Turf Grasses. At first yellow patches appears which turn red brown then the leaf blades turn whitish and die. This forms bare areas and (Colletotrichum species) forms spine-like fruiting bodies that are tiny and can only be seen using a hand lens.

Wither Tip (Colletotrichum gloeosporioides) forms spots on the leaves and flowers and the stems form cankers that cause wilting at the top of the branches. Commonly found on Aucuba species.

Source and Dispersal

The fungal spores are dispersed by wind from infected plants or parts of plants. It is also dispersed by splashing water or contaminated stock.

Favoured Conditions

The fungus prefers cool humid climates and is not commonly seen in warm coastal regions and may continue living in dead wood, leaf litter or harvested fruit.

Affected Plants

The Anthracnose species is found shrubs, vegetables, trees particularly fruit trees such as mango or macadamia and large trees such as Platanus species.

                  Acer negundo

Acer species are infected by the Anthracnose (Gloeosporium aporcryptum). Irregular shaped light brown spots appear on the leaf, joining to form large dead brown areas and giving the leaf a scorched appearance. Leaves may be fully or partially damaged, often causing the leaf to die prematurely. During constant wet weather this can become a serious problem. Acer saccharinum (Silver Maple) and Acer negundo (Box Elder) are particular susceptible and small plants may be sprayed with a fungicide as the new foliage appears to help control infection

                  Agave species

Agave species are susceptible to Glomerella Leaf Blight (Glomerella cingulate). This causes dark coloured depressed spots to appear on the leaves. The leaf apex dies and the spreading rot in Orchid species can infect the pseudobulbs causing the death of the plant.  

Orchids such as Cattleya, Cymbidium, Cypripedium, Dendrobium, Epidendrum, Oncidium, Paphiopedilum, Phalaenopsis and Zygopetalum species are infected by Glomerella Leaf Blight (Glomerella cingulate).

Agrostis palustris (Bent Grass) is particularly susceptible to Anthracnose (Colletotrichum species) and (Microdochium bolleyi), but this fungal problem is also found on Cynodon dactylon (Couch), Lolium perenne (Ryegrass) and Festuca arundinacea (Tall Fescue). These grasses are infected in areas of poor drainage or where leaf wetness is prolonged. Low soil fertility may also contribute to infection and it is commonly found in coastal regions.

Anthurium species are susceptible to the Anthracnose (Gloeosporium minutum) which causes circular spots on the leaves, along the margins. These meld together forming dead brown areas that dry and fall out. It is commonly found in a glasshouse situation. The spadix is also infected by Spadix Blight (Colletotrichum gloeosporioides) which forms dark spots that enlarge, spoiling the flower.

Antirrhinum species are susceptible to the Anthracnose (Colletotrichum antirrhina) which attacks stems and leaves forming sunken oblong spots that are yellowish with a brown margin.

Cactus species are susceptible to anthracnose causing shot hole disease, which attacks the pads of Opuntia species (prickly pear). It appears and during the hot humid months of the year and is distinguished by the appearance of small brownish spots that turn grey with black spores under the drying skin. Control methods include removal of infected pads and treating wounds with disinfectant.

Digitalis species are infected by the Anthracnose (Colletotrichum fuscum). This fungus forms rounded spots that are purplish-brown and may have a purplish border. Fruiting bodies appear in the centre as the spots enlarge.

Leucadendron and Leucospermum species are susceptible to Anthracnose (Colletotrichum gloeosporioides). This causes the new growth to die back, leaf spots appear and cankers to form on the stems. It also causes damping-off of seedlings, which can be a major problem for Protea species as the fungus can be carried in the seeds.

Limonium species are infected by Wither Tip (Colletotrichum gloeosporioides). This is a serious disease causing spots on the leaf, flower and stems or rotting the crown.

Ribes species are attacked by (Pseudopeziza ribis). This infection causes circular brown-black spots on the leaves and premature defoliation of the plant. The spots may also appear on the petioles or stems. Infected areas may be sprayed with wettable sulphur weekly.

Schizanthus species are infected by Anthracnose (Colletotrichum schizanthi) which forms eater soaked areas on the stems and petioles, preferring new growth and maturing with canker-like lesions that girdle the stems.

Tilia species are infected by the anthracnose (Gnomonia tiliae), which forms light brown spots on the leaf venation, towards the tip and can defoliate an entire tree.

Spot Anthracnose (Elsinoe ilicis) infects Ilex cornuta forming black spots that may lead to leaf disorder.  Opuntia species are infected by (Gleosporium cactorum) in warmer regions.

Vaccinium ovatum is infected by (Gloeosporium minus) and commonly known as Fleck and appearing on the leaf and stems.

Viola species are infected by (Colletotrichum violae-tricoloris) which produces brown blotches with black margins on the leaves.

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.

Turf grasses should have well drained soils, high fertility and avoid excessive watering to reduce possible infection.

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

     Lichens

     Various Lichen Species

Description

A fungus and an alga growing in a symbiotic relationship.  The food producing alga is given support and shelter by the fungus.

Symptoms

Lichens are variable, occurring in many shapes, sizes and colours from flat to circular and may be leaf like crinkly or hairy.  The colour also varies from greenish grey to yellow or orange.  They occur on many surfaces including tree trunks, rocks, fences and roof tiles.  They cause little harm to living plants and certain types are attractive while others are unsightly.  

Fagus sylvatica     

Source and Dispersal

Contaminated areas, and is dispersed by wind or splashing water.

Favoured Conditions

Conditions are variable as some types prefer cool moist situations while others tolerate open exposed positions.

                 

        

Affected Plants

There are many plants that form lichens on the bark, particular old woody trees that are in shaded moist positions. Shrubs and Palms also form coverage of lichens on there stems under moist conditions.

Archontophoenix cunninghamiana     

Non-chemical Control

Under normal circumstances, unnecessary but lichens can be removed by scraping or scrubbing.

Chemical Control

Not normally required but lichens can be killed by spraying the fungicide copper oxychloride but take care as the chemical may damage certain building materials.

Note

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

DISEASE

 

   NAME

     Dieback (General)

     Various Dieback Causes

 

Description of the Problem

This is a problem that affects Eucalyptus and Corymbia species in Australia and is rarely the result of an individual organism with the one exception of Phytophthora cinnamomi. It also affects many ornamental trees such as Populus species. It is difficult to identify the exact cause of dieback but there are certain factors that contribute.

 

 

Trees that remain in cleared areas for pastures which are fertilised with superphosphate or treated with insecticide are most at risk. Insects repetitively attack such isolated trees reducing there vigour and with less trees there are less predatory birds or lizards.

The clearing of the land damages the overall ecology of the area and this imbalance results in excessive insects, salinity of the soil and changes to the water table.  Certain fungus has been named 'Die Back', infecting stressed trees and killing them from the top down, commonly during periods of drought.

 

Die-back (Phytophthora cactorum) initially causes the buds and leaves turn brown and die. This is followed by cankers that form on the branches, girdling and causing ringbark. All parts above the canker die and infection is found on Rhododendron species.

 

Appearance and Distribution of the Pest

Dieback has been a natural occurrence for hundreds of years but has increased significantly since clearing and cultivation of the land started during colonisation of the country

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Period of Activity

Dieback occurs throughout the year but is assisted by drought, fire and flooding. The trees are exposed to adverse climatic conditions putting them under greater stress. Dieback has also been attributed to heavy acidic soils.

 

Damage Caused

When a tree is suffering from dieback it normally has sparse foliage with suckering growth from the main branches or trunk. The leaves eventually shrivel and fall leading to the death of the branch and the tree will linger for a period of time but then suddenly die.

 

Susceptible Plants

There are many Australian native species and ornamental trees affected including Eucalyptus, Corymbia, Callitris, Lophostemon, Syncarpia and Casuarina species. Trees that are isolated singularly or in small groups as in pastures or along road sides are most at risk.

 

Alectryon excelsus is susceptible to an unknown Die Back that has recently infected trees. The symptoms include the new growth shedding leaves and the stems die. New growth occurs on live wood but once again it suddenly dies off. This repetitive defoliation reduces the trees vigour. Currently there is no current control methods.

 

Betula species are susceptible to the Die-Back (Melanconium betulinum) which kills the upper branches and eventually the tree.

 

Fraxinus excelsior is susceptible to a chronic fungal disease caused by the ascomycete fungus (Hymenoscyphus fraxineus) that results in leaf loss and crown dieback.

 

Pseudotsuga menziesii Douglas Fir is infected by the fungal Die Back (Dermea pseudotsugae). Symptoms include the foliage and branches turning brown and dieing from the apex and normally attacks young plants. There is no current control method.

 

Taxus species are also affected by dieback.

 

Cultural Control

It is very complex problem and individual trees may be saves by dealing with the insect problem but generally the ecology of the region needs to be addressed. This is very difficult to do as new plantings are also attacked or affected by saline soils.

 

Chemical Control

There is no chemical control for this problem.