Trichopoda pennipes

Trichopoda pennipes is about the size of a large housefly, and is primarily a parasite of insects in the families Coreidae (squash bugs and leaf-footed bugs) and the Pentatomidae (stinkbugs). Although several species of Tachinid flies have been imported as biological control agents of agricultural pests, this distinctively colored fly is native throughout much of the United States.

T. pennipes appears to have different biotypes across the country, preying on very specific hosts in different regions. In California, a population of the fly was reported attacking the bordered plant bug (Largus succinctus fig. 1), but the same flies never attacked the squash bug. [1]  Recently, T. pennipes were collected from fields of squash in New York state and released near farms growing squash in northern California. They have now established permanent populations, and now nearly 50% of the squash bugs preying on the plants are found with fly eggs deposited on them. However, it is not known how effective is this control, or whether the flies have managed to reduce populations of the voracious crop pests. (I'm privately wondering what other "unintended consequences" have arisen from this experiment, and gone undetected).

In Nezara viridula (figure 2), a species of stinkbug originating in Ethiopia that has spread worldwide and become a pest of crops in many regions, the defensive secretions (what puts the "stink" in stinkbug) are effective deterent to many predators, but T.pennipes appears to be tolerant of the chemicals. Indeed, T. pennipes appears attracted to N. viridula's pheromones which mediate sex attraction in the bug. [2] Chemical warfare amongst the insects is an extremely complex and highly evolved adaptation.

Trichopoda pennipes is commonly called the "fringe-legged" fly.