Colour - Brown or green. (Horehound bug is red and black).
Body - Up to 15mm long and 10mm wide. Broad .Shield shape.
Wings - 2 Pairs, both used in flight. Held flat and overlapping position when at rest. Coupled. Wing-span 25mm.
Mouthparts - Stylet. Sucking. Near rear of head.
Antennae - 5 segments in adults, 4 in nymphs.
Eyes - 2 Compound. 2 simple.
Legs -Feet (Tarsi) have 4 segments.
Head -Wedge shaped
Thorax - 3 segments. Large triangular plate (scutellum) in the middle of the back.
Abdomen - Eight pairs of spiracles on underside.
Egg - ovoid. Pale yellow.
Habits - Can't fly when cold. Give of an obnoxious odour threatened. Tend to congregate.
Similar to adults. Usually 5 stages (instars).
Adults over-winter in sheltered crevices. In spring and early summer large numbers of eggs are laid in rows on leaves. These hatch to produce nymphs that grow quickly and moult 5 times. They look and behave similarly to the adult. In 5 weeks they have reached full size. Often develop into large numbers in hot dry summers. There may be several generations each year. Tend to fly in hot weather.
Origin and History:
Introduced green vegetable bug (Nezara viridula) is a pest of lucerne, beans, tomatoes and other vegetables. The similar looking and native Glaucias amyoti is a minor pest of vegetables in Queensland. Horehound bug (Agonoscelis rutila) attacks the horehound weed. The spined citrus bug (Biprorulus bibax) attacks citrus and Rutaceae. The green potato bug (Cuspicona simplex) feeds on potatoes. Some species eat caterpillars.
One species is predatory on the Brown Pasture Looper which is a pest of pastures and crops.
Management and Control:
Spaying is economic on some crops.
Aphids, Lerps, various bugs, leafhoppers and scales.
CSIRO. The Insects of Australia. Melbourne University Press. (1991) p508,509.
Goode, J. Insects of Australia. Angus and Robertson. p69.
Victorian Department of Agriculture. Insect Bulletins. p52.
Collated by HerbiGuide. Phone 08 98444064 for more information.