I think Conops quadrifasciatus, Hutchinson's bank The females of Conops quadrifasciatus specialise in attacking bumblebees in flight. They wait on flowers for a bumblebee to arrive and then hijack the bee and whilst holding on inject an egg into the bee's abdomen. The egg hatches inside the bee and the larva feeds on the bee's abdominal contents. The bumblebee eventually dies and the larva then pupates and emerges the following summer.