2,000 described species in the world. Estimated total: 5,000–10,000. In the Nearctic, 299 spp.
Exactly 18 antennal segments (Scape, pedicel, and 16 flagellomeres; in some microgastrines, some segments appear subdivided
Spiracles of first metasomal segment situated on lateral tergite rather than medial tergite
Larvae are parasitoids of various Lepidoptera larvae.
is the most common genus of Microgastrinae. Acta Zoologica
Females of this subfamily inject POLYDNAVIRUSES into the host during oviposition. These virus particles compromise the host immune system, protecting the parasitoid progeny. Click here
for more information on this fascinating example of mutualism.
Muesebeck, C. F. W. (1922). A revision of the North American Ichneumon-flies belonging to the subfamilies Neoneurinae and Microgasterinae. Proc. U.S. Nat. Mus. 61(15): 1-76 (Full Text
1st page of Microgastrinae entry
from the 1979 "Catalog of Hymenoptera of America north of Mexico(1)
" (AKA "the Red Book"). Some of the nomenclature may be outdated, but nevertheless a useful reference (especially for hunting down synonymy & literature for various taxa).