Stink Bugs or Shield Bugs

Gum Tree Shield Bug, Theseus modestus, nymph (top) and adult (above)  Bronze Orange Bug adult, Musgraveia sulciventris The flat nymphs, orange with black spot and rim, are very different from the adult Bronze Orange Bugs.

Both the adults and nymphs of stink bugs secrete a corrosive, smelly substance as a chemical defence against predators. This fluid has a repulsive smell and can be very painful if it gets in your eyes. If this does happen, wash your eyes with copious amounts of water or saline solution. There are more than 550 Australian species of stink and shield bugs, most in the Family Pentatomidae.

Gum Tree Shield Bug
Theseus modestus (Family Pentatomidae)

The black and white nymphs of the Gum Tree Shield Bug occur in clusters under the loose bark of living gum trees. The adults are better camouflaged and roam more freely on the trunk where they suck the sap from the bark and also feed on Eucalypt Planthopper eggs. Gum Tree Shield Bugs are found in open forest, Australia-wide

Identification

Length about 15 mm. The adults are mottled grey and black with a white tip to the scutellum. The nymphs have a round body and are darker coloured with white markings. Gum Tree Shield Bugs belong to the Family Pentatomidae which has over 390 species in Australia.

Bronze Orange Bug
Musgraveia sulciventris (Family Tessaratomidae)

Biology

Bronze Orange Bugs suck sap from the shoots of citrus plants, and when in large numbers can cause them to wilt. Adults and nymphs secrete a corrosive, smelly substance and are able to squirt it a considerable distance.

While its native food plants are wild limes, the Bronze Orange Bug has become a pest of cultivated citrus. This species is found in forests, gardens and citrus orchards in coastal areas from Rockhampton, Queensland to Wollongong, New South Wales.

Identification

Length about 25 mm. The large adults have a broad, dark bronze body with a triangular scutellum in the middle of back. The very flattened nymphs are orange with a central black spot. Bronze Orange Bugs are one of 15 Australian species belonging to the tropical Family Tessaratomidae.

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