Microgastrinae


Microgastrinae is a subfamily of braconid wasps, encompassing almost 3,000 described species, with an estimated 30,000–50,000 total species. This makes it one of the richest subfamilies with the most species of parasitoid wasps.

Genera

These 84 genera belong to the subfamily Microgastrinae:
These wasps are small, with 18 segmented antennae. Most species are black or brown, a few are more colorful. Many species are morphologically similar enough to be considered cryptic species. Species within this subfamily have a worldwide distribution. 135 species of Microgastrinae have been confirmed from Canada, though the number may be as high as 275. At least 28 species have been identified from Turkey in Gökçeada and Bozcaada.

Biology

Microgastrinae are koinobiont, primary endoparasitoids of larval Lepidoptera. While most species are solitary, many are gregarious, meaning multiple wasp eggs develop within the same caterpillar. When the eggs hatch the wasp larvae feed on the hemolymph and organs of their host. Once fully developed, the larvae exit the dying caterpillar and immediately spin silken cocoons where they pupate.
Microgastrinae is one of six subfamilies of Braconidae which carry polydnaviruses.
More than 100 species of Microgastrinae have been used in biological control programs.

Coevolution with polydnaviruses

Microgastrinae need the virus to be able to reproduce. How it is exactly done is by injecting eggs with the proviral genome plus virions into the host's cavity. The virions then infect and discharge their DNA into the host's cells, stopping it from killing the wasp's offspring and instead promoting its growth inside the host's body.