Taxonomic Relationships of Parasitoid
Sweet man (1936) recorded different groups of parasitoid belonging to 5 orders containing 86 families with insect hosts. Orders in which parasitoids recorded are Coleoptera, Diptera, Hymenoptera, Lepidoptera and Strepsiptera. However, in order of importance order Hymenoptera (wasps) and Diptera (flies) are mostly used in biological insect pest suppression. Order Hymenoptera contains roughly 2 to 5 lakh species of parasites. Townes (1972) estimated that only about 5% of the parasitic species had been described and of these numbers, the biological information was available on approx for only 3% species. In classical biological insect pest suppression programmes, the parasites predominantly used belong to super families Ichneumonidae, Braconidae and Chalcidoidea.
The Ichneumonidae usually include the largest of the beneficial wasps associated with host larvae and pupae. The Braconids on the average are usually much smaller than the Ichneumouids. The Diptera ranked next in importance to Hymenoptera in biological insect pest suppression programmes. The families of Diptera exclusively parasitic are cytidae, Nemestrinidae, Pipnculidae, Conopldae, Pyrgotidae and Tachinidae, as well as Bombylidae.