Fairyflies (Hymenoptera: Mymaridae)

The family Mymaridae is cosmopolitan, occurring in all terrestrial habitats and also in freshwater ponds and streams. The greatest generic diversity occurs in Australia, New Zealand and South America, but the greatest number of species is probably in tropical forests. The northern hemisphere, particularly Europe, is relatively depauperate, with about one quarter of the genera. Mymarids form an important component of any chalcid fauna, making up at least 5–10% of the individuals of Chalcidoidea collected by methods such as Malaise traps or pan traps.

This family is one of the few chalcids groups with a common name – fairyflies – derived from the fact that individuals of most of the species are such small insects that most people have never seen them. Indeed, the family includes the smallest recorded insect: the wingless, eyeless males of Dichopomorpha echmepterygisMockford, that live as parasites in barklouse (Psocoptera) eggs. Four males lined up end to end would extend the diameter...