Like the vast majority of tachinid flies, T. brevifacies is a parasitoid of other insects, specifically late larval stages of a number of species of Lepidoptera.

Trigonospila brevifacies is native to the eastern states of Australia and has been collected from Tasmania, New South Wales, Victoria, and southern Queensland.

It is believed T. cingulata is a parasitoid of chrysomelid beetle larvae in the genus Paropsis, which are abundant herbivores in many Australian environments.

The black and white abdominal markings of T. cingulata are continuous, crisp stripes from the dorsal to ventral sides of the abdomen, whereas the black markings of T. brevifacies typically are more or less triangular spots on the anterior margin of each the third, fourth, and fifth abdominal tergites which may or may not be quite diffused.

Some of these are non target species and T. brevifacies is found to compete with many native parasitods [6] Carposinidae Gelechiidae Geometridae Tortricidae Oecophoricae Pterophoridae Pyralidae Stathmopodidae