RAPD-PCR with Parasitic Hymenoptera

The parasitic Hymenoptera represent a group of insects that is both taxonomically and biologically poorly defined, despite the fact that members of the group are the premier agents in successful programs for the biological control of phytophagous insect pests. The vast majority of Hymenoptera utilize a parasitic lifestyle. Most Hymenoptera families contain parasitoid species, but some of the same families also include nonparasitoids. Although more than 100,000 species of Hymenoptera have been described, it has been estimated that more than 75% of the parasitic species have not been identified (1 ,2 ). Contributing factors to this lack of knowledge of parasitic Hymenoptera species are their diminutive size and their relative rarity under most conditions. The insects generally are slender with individuals of many species less than 5 mm long. At least one species of Trichogrammatid has an adult size of about 0.2 mm, which could be the world’s smallest insect (2 ). Parasitic Hymenoptera have the capability to respond quickly to an outbreak of their phytophagous hosts, however, under stable equilibrium conditions the population density of the parasites may be very low (1 ).