Males of Dicopomorpha echmepterygis, a wasp in the family Mymaridae, are the smallest of all insects. These males are blind and wingless and may be no more than 0.139 mm in length, the smallest known adults of any insect. Their tiny bodies, neatly packaged with complete digestive, reproductive, respiratory and circulatory systems are actually smaller than a single-celled paramecium. Obviously, the eggs and larvae of this wasp are considerably smaller than the adult.

This species from Illinois is an idiobiont parasitoid of the eggs of a lepidopsocid barklouse, Echmepteryx hageni. The adult males mate with their sisters inside the host egg, and die without ever leaving the egg; similar life histories can be found in the wasp family Trichogrammatidae, also in the superfamily Chalcidoidea.

Reference

Mockford, E.L. (1997) A new species of Dicopomorpha (Hymenoptera: Mymaridae) with diminutive, apterous males. Ann. Ent. Soc. America 90: 115-120.

Wasps

Dicopomorpha echmepterygis