Over 1,000 species worldwide.(2)
generally less than 5 mm; often 2-3 mm.
Very large marginal cell is the hallmark for several genera in this subfamily.
The vertex of head has a unique shape.
An interesting feature of this subfamily is that the mandibular action is opposite to other wasps. To visualize, place the backs of your hands together and then move your fingers outward.
Comment from Joseph Fortier on the second of the above images: "What gives this braconid away as an alysiine is the last (closeup) shot, showing the truncated, outwardly curving mandible. Alysiine wing venation is often closely similar to that of Opiinae, another fly parasitoid. Alysiines use these specialized mandibles for digging out of the tough fly puparium after emergence from their own pupae."
Adults feed on pollen and nectar. Larvae feed on immature cyclorrhaphous fly life stages.
Female alysiine wasps lay their eggs in the eggs or maggots of their hosts, and emerge from the host puparium after eating and killing the host. Thus they are "egg-pupal" or "larval-pupal" parasitoids. The hosts are cyclorraphous Diptera, which are flies with short antennae in which the adult emerges through the hard puparium through a circular opening. In the case of a parasitized fly puparium, the wasp emerges instead of the adult fly.(2)
Parasitoids of cyclorrhaphous Diptera.
Compare mandibles of Opiinae:
Wharton, R.A. Subfamily Alysiinae. In
: R.A. Wharton, P.M. Marsh, and M.J. Sharkey. 1997. Manual of the New World Genera of the Family Braconidae (Hymenoptera). (2)