We didn’t identify this fly down to the species, but we figured out the family. Some tachinid flies parasitize pest species, which has allowed them to be used as biological control agents by farmers. For instance, Istocheta aldrichi only attacks the Japanese beetle. But some are generalists; Compsilura concinnata uses at least 200 different hosts, and so is not safe to be used as biological control.

Adult tachinids feed on flowers and nectar from aphids and scale insects. As many species typically feed on pollen, they can be important pollinators of some plants, especially at higher elevations in mountains where bees are relatively few. So don’t be hating on them, just because they’re flies!