Family TRICHOGRAMMATIDAE
Introduction
The Trichogrammatidae is a medium-sized family. Although relatively common, they are often overlooked due to their extreme small size (usually less than 1 mm). All known species are primary (solitary or gregarious) egg-parasitoids, with most hosts in the Homoptera, Lepidoptera and Coleoptera, although many other host orders are also attacked. Some species are phoretic upon the adults of their hosts. Species of Trichogramma, which is the largest genus and the best known biologically, appear to be quite indiscriminate in host preference, and will attack any suitable sized egg they encounter.
Economic Importance. Trichogrammatids are used very widely in biological control, usually through the method of mass-rearing and inundative release.
Distribution. Cosmopolitan.
Classification. The Trichogrammatidae are not further divided into subfamilies.
Important genera: Trichogramma, Oligosita, Aphelinoidea, Ufens.
Identification of Australian genera: There are no keys to Australian genera. Doutt & Viggiani (1968) provided keys to world genera; Noyes & Valentine (1989) provided keys to New Zealand genera.
Diagnosis
Tarsi 3-segmented. Antenna with 4 or less funicular segments. Postmarginal vein usually absent. Small to minute insects (usually less than 1 mm in length) which parasitise insect eggs. Many species have the setae on the wing arranged into rows.
General References
Doutt, R.L. & Viggiani, G. 1968. The classification of the Trichogrammatidae. Proceedings of the California Academy of Sciences 35(20): 477-586
Noyes, J.S. & Valentine, E.W. 1989. Chalcidoidea (Insecta: Hymenoptera) — introduction, and review of genera in smaller families. Fauna of New Zealand 18: 1-91