The armoured beauty here is Bronze Orange bug, or Shield Bug of Queensland and New South Wales. According to the Queensland Museum, it is also called Musgraveia sulciventris.
These bugs suck sap from the shoots of citrus plants, and when in large numbers can cause them to wilt. This was the case at my friend’s house where the bugs completely took over her lime tree. Adults and nymphs secrete a corrosive, smelly substance and are able to squirt it a considerable distance.
It is hard to imagine that such a beautiful thing could be so smelly and cause so much damage. The orange bugs are part of the tropical Family Tessaratomidae, and there are 15 of them in total. They grow to 25mm long.
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.