They go through hypermetamorphosis. The female deposits eggs on flowers frequented by bees. The first instar is a planidum
, an active larva capable of climbing on a bee or bumble bee (their hosts). They are transported to the bee nest where they behave as parasitoids. The following instars don't have legs and feed on the bee larvae and stored pollen and nectar.
1. Eggs. 2. Triungulin