The Trichogrammatidae are a family of tiny wasps in the Chalcidoidea that include some of the smallest of all insects, with most species having adults less than 1 mm in length. The over 840 species are in about 80 genera; their distribution is worldwide. Trichogrammatids parasitize the eggs of many different orders of insects. As such, they are among the more important biological control agents known, attacking many pest insects (esp. Lepidoptera).