The Platygasterids (192 NA spp) are minute, shining-black with short antennae
and resemble Chalcids. Most are parasites of the larvae of Cecidomyiid
midges. They are quite common in old field sweeps but are easily overlooked
because of their small size. Perhaps 10+ species in the genera Platygaster,
Amblyaspis, Fidobia, Isocybus,
Isostasius, Polymecus,
Trichasia, and
Inostemma
have been collected. Species of
Inostemma are easily recognized
by the hooked ovipositor sheath extending over the back.
