What is the smallest insect?

The smallest insect is a fairy wasp. More precisely, males of Dicopomorpha echmepterygis, a parasitoid wasp in the family Mymaridae, hold the record for shortest known insect body length.

Measured males average about 186 micrometres long, with recorded specimens ranging from 139 to 240 micrometres. Females are much larger, about 550 micrometres, illustrating the species’ extreme sexual dimorphism. The males are wingless and blind, and they can mate inside their host’s egg before dying without leaving it.

This tiny wasp develops as a parasitoid of barklouse eggs. “Fairy wasp” describes a family group rather than one single species, so the quiz’s answer is correct at the usual common-name level. A related fairy wasp, Kikiki, is often described as the smallest known flying insect, but it is not the smallest insect overall.