Overview
All known species are primary (solitary or gregarious) egg
-parasitoids,
with most hosts in the Hemiptera: Auchenorrhyncha (bugs), Lepidoptera (moths and butterflies), and Coleoptera (beetles), although many other host orders are also attacked. Some species are phoretic upon the adults of their hosts, where the host transports the trichogrammatid with it. 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 suitably sized egg within a particular niche. Trichogrammatids are used very widely i
n biological control, us
ually through the method of mass-rearing and inundative release.
Description
The Trichogrammatidae, although relatively common, are often overlooked as they are among some of the smallest known insects (0.2 1 mm). More than 140 species are described for Australia and seven for New Zealand. Trichogrammatids are characterised by 3-segmented tarsi, antenna with four or less funicular segments, and postmarginal vein of the fore wing usually absent. In addition, many species have the setae on the wing arranged into rows.
Distribution
There are no keys to Australian genera, although Doutt and Viggiani (1968) provide keys to world genera, and Noyes and Valentine (1989) to New Zealand genera.
Further information about the Trichogrammatidae can be found in Doutt & Viggiani 1968, Gibson 1993, Naumann 1991, Noyes & Valentine 1989 and Noyes 2001.