This species feeds on seeds of Wattle and Hop Bush while they are still on the tree. In the above photos they are on Black Wattle but were not feeding since there was no mature seed at the time
Classification
from Australian Faunal Directory
Order Hemiptera - bugs, hoppers and scale insects
Suborder Heteroptera - true bugs, 2806 named species in Australia
Superfamily PENTATOMOIDEA - Shield Bugs, 572 named species in Australia
Family SCUTELLERIDAE - Jewel Bugs, 28 species in Australia
Genus Coleotichus
Species Coleotichus costatus