Syrphid Predators for Biological Control of Aphids

Abstract

The family Syrphidae is divided into three subfamilies viz., Syrphinae, Milesiinae and Microdontinae. Majority of aphidophagous syrphids belong to the subfamily Syrphinae. Most species are terrestrial, while a few species are aquatic or live in very moist situation. Among the terrestrial forms at least 25 per cent are predacious, chiefly aphidophagous. There are more than 4700 species worldwide with 312 species under 71 genera known from the Indian subcontinent. Many studies have been conducted on the biology, intrinsic rate of increase, feeding behavior and factors affecting their oviposition and techniques for their multiplication. Relatively, less importance has been given to their field evaluation and to the studies dealing with reasons tracing causes for their less effectiveness in the open field. Recently, considerable efforts have been made to enhance their effectiveness by manipulating their habitat. Development of techniques for their effective shipment and release are necessary. Release rates, stage to be released, and stage which can be stored at low temperature need to be identified.