Biosystematics of Tachinidae

 Biosystematics of Tachinidae:

Diptera are two winged, or “ true”, flies. Although the parasitic Diptera are not quite so biologically diverse as the parasitic Hymenoptera, they are parasites on hosts from more animal groups. Family Tachinidae (Tachinidae, from the Greek Taxivas, a here, from Taxivas, swift) referring to the active adults. German, Raupenfliegen Tachina (tachina) Flies; Tachinid Flies. They are ecologically important in balance of nature because larvae are parasites in other insects, spiders, woodlice and centipedes; employed in biological control of pests. It consists of about 300 genera and 5,000 species, distributed throughout the world. In North America there are some 190 genera and 1,500 species (Essig, 1982). In Southern Asia about 18genera and 30 species of tachinidae are recorded. In India 15 larval tachinid and 7 larvo-pupal parasitoids are recorded on H. armigera on cotton (Lingappa et al., 2001). Achan et al., (1968) recorded 17 species on different crops. On H. assulata 4 and on H. peltigera 6species of tachinidae are reported from Asia.

DeBach (1943), placed parasitoid according to egg laying habits as i.e. (i) oviposition apart from the host (ii) oviposition on the host and (iii) oviposition in the host e.g. in S.illota, oviposition is of second type. Eggs deposited allover the body. Van Emeden (1954) divided the Tachinidae into five sub-families as Phasiinae, Dexiinae, Macquartiinae, Tachininae, and Goniinae e.g. Gonia, Nmorilla, Carcelia, and Zenillia. All 30 species of tachinidae belong to subfamily Goniinae and play major role in control of H.armigera. Askew (1971) has given the modifications in Tachinidae, into six groups as (1) in some larvae or eggs are laid apart from the host on leaves or the surface of soil.  The eggs must be minute.  One female may lay upto 6000 eggs. (2) Larviparous or ovoviviparous place their progeny to the host's body. (3) Oviparous, eggs laid on foliage.  The eggs are very small (microtype), usually less than 0.2 mm long. (4) Oviparous, lay large eggs (macrotype) on the host.  The egg approaches one millimeter in length and may be soft shelled and attached to the host hair by stalk (Carcelia) (100 to 200 eggs). (5) Oviparous species that insert their thin-shelled eggs into the host by means of a piercing substitute ovipositor. (6) Larviparous or oviparous, introduce their progeny inside the body of host by a piercing apparatus. These modifications help for identification and classification of tachinidae.