Members of the family Trichogrammatidae (Hymenoptera: Chalcidoidea) are parasitic on the eggs of other insects, and are among the smallest members of the insect world, ranging in size from 0.2 – 1.5 mm. Trichogrammatidae currently consist of about 800 species in ca. 80 genera worldwide. The family is known from all vegetated terrestrial habitats, and attacks a wide range of hosts.
Several classifications of the family have been proposed, though the most commonly used classification is based largely on male genitalia and divides the family into 4 tribes, each with its own genitalic ‘theme’ based on varying levels of simplification. However, morphological studies of the family are still in their infancy and we are years away from a robust morphological phylogeny. Therefore, this family may benefit from molecular analysis more than most.
Molecular investigations of the family are focusing on the 28S rRNA domains D2 and D3. To date, approximately 50% of the currently recognized genera have been sequenced. Although molecular studies with limited taxonomic sampling have indicated that the Trichogrammatidae are monophyletic, this is the first attempt to broadly sample generic diversity of the family in an attempt to elucidate intrafamilial relationships.
The molecular phylogeny does not match the relationships predicted by the current classification. Nonetheless, some historically recognized groups have been recovered in our analyses, suggesting that the characters used in the current classification are of some value. However, results suggest that a new higher level classification of the family will need to be proposed.
Species 1: Hymenoptera Trichogrammatidae
Keywords: parasitoid
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