Physoconops

The conopid flies are out. One landed on my tomato plant the other day. Ferocious and strange, these flies are among the most sinister and most impressive two-winged hunters. This group is distributed worldwide, and probably fairly old. The larvae are always parasites of aculeate hymenoptera-ants, bees, wasps, and the like. Adult female conopids aggressively intercept female bees and wasps in flight, and lay eggs on the underside of the host. The female conopid has a modified abdomen that can actually pry open the sternites on the underside of a bee, like a can opener, and lay the eggs right where they can hatch and crawl into the victim. The victim will continue to live for a while, as the larvae eat the internal organs and muscular tissues. The flies actually pupate inside the dead bees before they emerge. Apparently, the conopids have their own natural enemies. Parasitic chalcidoids can somehow hyperparasitize conopid larvae, and pupate within the pupae of the flies, which lie within the dead bee.