PEST

NAME
Bugs (General)
Various Bug Species

ORDER
Hemiptera

Description of the Pest
Generally bugs are sap sucking insects with a strong proboscis and are commonly shield shape. They may be dull grey-brown or brightly coloured with long anatine and legs. They feed in colonies or solitary and cause excessive damage due to the toxic saliva they inject into the plant. They also are capable of emitting a nauseous smell or squirting a caustic fluid when disturbed or they fly away. Both adults and nymphs have piecing and sucking mouthparts and adults commonly shelter under plant litter or under bark during winter.

      Cotton Harlequin Bug (Male)

Cotton Harlequin Bug (Tectocoris diophthalmus) adult female is up to 20mm long and is orange-yellow with black patches on its wing covers. The smaller male is reddish with bright metallic blue or green markings. Eggs are laid in a spiral arrangement around twigs and both eggs and nymphs are guarded by the adult female.
Adults and nymphs have piercing and sucking mouthparts and cause little damage to the host plant, though may be found in large numbers. They appear during late winter and are more prevalent along coastal regions on plants from the Malvaceae family such as Lagunaria patersonii. Control is not normally warranted.

Crusader Bug (Mictis profana) is a light brown elongated bug to 20mm. It has distinctive pale yellow cross mark, depressed on its back and large rear legs. It has long antennae that are tipped in yellow and when disturbed can secrete a foul smelling caustic fluid. The immature stages (nymphs) are brownish with no cross and marked with two small orange spots on the abdomen.
Both adult and nymph have piecing and sucking mouth parts and are solitary feeders on tender new shoots causing wilting and dieback. They are found on a wide range of plants including Hibiscusand Acaciaspecies and normally do not require control.

Eucalyptus Tip Bug(Amorbus alternatus) adult is a blackish shield-shaped insect up to 20mm long with a spine on each shoulder. The wing covers are marked with a yellowish 'V` pattern and the lava are brightly coloured in shades of blue and orange with its body tapering towards the head.

Harlequin Bug

Harlequin Bug(Dindymus versicolor) is very colourful with red or black upper parts and a green to yellowish abdomen and is up to 12mm long. The wingless nymphs are also brightly coloured and are commonly found in temperate climates on plants and structures such as fences. .

There is also another Harlequin Bug(Murgantia bistrionica) that is found in North America and has simular colourings, habits and grows to 10mm long. The adult lays eggs in double rows on the underside of leaves.

Metallic Shield Bug(Scutiphora rubromaculata) is up to 10mm long. The adult is brightly coloured in metallic blue with two obvious red blotches on its thorax. It is found in tropical to sub tropical regions.

Plant Bug(Hallicotoma valida) is small and blue-black, which slightly engraves the epidermal layer of the leaf turning it yellow and is found on Yuccaspecies.

Rutherglen Bug(Nysius vinitor) is dull grey with silvery wings that up to 5mm long and the winged nymphs are also grey.

Bronze Orange Bug Bronze Orange Bug Nymph

Appearance and Distribution of the Pest
Generally nymphs appear in winter after hatching from eggs that were laid in late summer under the leaves, generally unnoticed apart from a strong smell.
They are found throughout the world in tropical, sub tropical to temperate regions. They appear from late winter to late autumn and can be seen on the new growth and fruit.

Rutherglen Bugcan form large colonies causing the new growth to wilt or stem tissue forms a dry area. It can become a serious pest requiring control.

Life Cycle
These insects have a Hemimetabolouslife cycle, ie. When the immature nymphsresemble the adults.
There are five nymphal stages with the eggs laid during late winter and up to 4 generations each season. Certain species of adults tend the eggs until they hatch. The insect over winters as an adult.

     Harlequin Bug

Period of Activity
This pest is active throughout spring and summer, with large numbers occurring in autumn.

Damage Caused
Generally the nymphs and adults feed on new shoots, the underside of leaves, flowers and stems of plants and mature bugs feed on fruit or seeds. This causes bean pods to become shrivelled and distorted, or tomatoes form mottled areas and peaches exude clear gum. Leaves and flowers wilt or shrivel and die. The North American Harlequin Bug forms white or yellow blotches on the leaf surface causing plants to wilt and die.



Susceptible Plants
There is a wide range of plants that are attacked by various bugs including legumes such as beans or lucerne or pumpkin, spinach, passionfruit and many ornamental and native trees and shrubs. Fruit trees and weeds are also attacked.

Abutilon, Alyogyne, Hibiscusspecies, Vitis vinifera(grape) and Lycopersicon esculentum(tomato) are susceptible to attack by Harlequin Bug(Dindymus versicolor) causing damage to new growth and blemishing fruit with there excrement. Many vegetables and fruit trees are also susceptible to attack.

Abutilon, Alyogyne, Hibiscusspecies are also attacked by the CottonHarlequin Bug (Tectocoris diophthalmus).

Eucalyptusspecies are attacked by the Eucalyptus Tip Bug(Amorbus alternatus). The slow moving adults suck sap from the host solitary or in groups causing wilting and sometimes dieback of the branches. It is not regarded as a major pest and control is not normally required.

Ficusand Melaleucaspecies are attacked by theMetallic Shield Bug (Scutiphora rubromaculata).

Acacia, Cassia, Citrus, Hibiscus, Sennaspecies and Vitis viniferaare susceptible to attack by the Crusader Bug(Mictis profana) damaging new shoots.

Leucanthemum species are attacked by the Four-lined Leaf Bug(Poecilocapsus lineatus). The adult is yellow with four black stripes on its wings and attacks the leaves causing spotting that turns them brown, eventually dieing.

Pennisetum clandestinum(Kikuyu) is attacked by theBillbug(Spenophorus brunnipennis). This weevil produces larva that can be seen at the soil level and are legless up to 10mm long with a brown head and a cream coloured curved body. During early summer affected leaves turn yellow and a second generation may occur in late summer.
Bluegrass Billbug (Sphenophorus parvulus) attacks Poa pratensis(Kentucky Bluegrass).

Cultural Control
Small infestations may be carefully removed by hand or hosed off then collected. Heavily infested plants or plant parts may be removed and destroyed. Weed control around the plants may increase possible infestation as the bugs migrate to a new host. A barrier of annuals may be planted around susceptible plants as to attract the bugs once the annual weeds die off.
Remove all rubbish such as woodpiles or garden wast or rubbish from the garden as bugs tend to shelter in these areas. Susceptible plants may be sprayed up to three times during the cooler months with a soapy or glue spray on both sides of the leaves in order to kill the nymphs.
Hosing may also dislodge adult bugs and once on the ground they can be squashed. Another novel method for removal is to use an electric or portable vacuum cleaner to suck the bugs from the host plant. This method is excellent on several species including stink bugs and Christmas beetles.

BiologicalControl
Bugs are attacked by many predators including; birds, spiders, assassin bugs, parasitic wasp and parasitic fungi. These predators combined still have little control over infestation of susceptible plants.

Assassin Bug Nymph

Chemical Control
Spraying with insecticides is effective, such as Fenthion, Maldison or Dimethoate. Always read the label for registration details and direction of use.
Note
Always read the label for registration details and direction of use prior to application of any chemicals.