In Australia, T. brevifacies and T. cingulata are common within their respective ranges and can often be found resting on vegetation.

Trigonospila are strikingly patterned flies; primarily black with pearly whitish to golden transverse bars on the thorax and abdomen.

[11] T. brevifacies is a polyphagous parasitoid of the larvae of Lepidoptera and is native to the eastern states of Australia with a range extending from Tasmania to southern Queensland and possibly as far west as South Australia.

T. brevifacies has been deployed in New Zealand as a biocontrol agent of a number of agricultural pests including the light brown apple moth Epiphyas postvittana (Lepidoptera : Tortricidae) and the potato tuber moth Phthorimaea operculella (Lepidoptera : Gelechiidae).

[10] T. cingulata and T. fasciata are believed to be parasitoids of chrysomelid beetles in the genus Paropsis,[10] some of which may be pests of agriculture or forestry.