Identification, Images, & Information
For Insects, Spiders & Their Kin
For the United States & Canada

Subfamily Microgastrinae

Nest? Braconid Wasp Braconid ex oak-mining Acrocercops - Sathon - female Wasp - female Unidentified cocoons (?) on Baccharis pilularis leaves pupae Braconid? on milkweed - male Braconidae, lateral
Classification
Kingdom Animalia (Animals)
Phylum Arthropoda (Arthropods)
Subphylum Hexapoda (Hexapods)
Class Insecta (Insects)
Order Hymenoptera (Ants, Bees, Wasps and Sawflies)
No Taxon ("Parasitica" (parasitic Apocrita))
Superfamily Ichneumonoidea (Braconids and Ichneumons)
Family Braconidae (Braconid Wasps)
Subfamily Microgastrinae
Numbers
2,000 described species in the world. Estimated total: 5,000–10,000. In the Nearctic, 299 spp.
Size
1-4 mm generally.
Identification
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
Range
Cosmopolitan
Food
Larvae are parasitoids of various Lepidoptera larvae.
Remarks
Cotesia 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.
Print References
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)


Whitfield, J. B. (1995). Annotated checklist of the Microgastrinae of North America north of Mexico (Hymenoptera: Braconidae). Journal of the Kansas Entomological Society, 245-262.
Internet References
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 Some of the nomenclature may be outdated, but nevertheless a useful reference (especially for hunting down synonymy & literature for various taxa).
Works Cited
1.Catalog of Hymenoptera in America North of Mexico
Karl V. Krombein, Paul D. Hurd, Jr., David R. Smith, and B. D. Burks. 1979. Smithsonian Institution Press.