Rhopalosyrphus

This is a myrmecophilous genus of Syrphidae with nine species. Rhopalosyrphus Giglio-Tos is a small group of microdontine flower flies restricted to the New World subtropics and tropics, ranging from southern United States to northern Argentina. These flies are rarely collected, only some two dozen specimens are known. The adults mimic eumenine vespids, such as Zethus, which nest in twigs (Bohart & Stange 1965). The immature stages are known for only one species. These were found in ant nests (Pseudomyrmex) in twigs and grass culms, where the larvae probably prey on ant brood.