Abstract: Predatory syrphids are a group of common natural enemies of cotton aphids in northern Xinjiang. The species composition and population abundance of predatory syrphids on different plants were examined through systematic investigation on different plant species in 2014 and 2015. The results indicate that Sphaerophoria, Paragus and Syritta are the dominant genus. Sphaerophoria scripta, Sphaerophoria rueppelli, Paragus compeditus, and Syritia pipiens are the dominant species. Episyrphus balteatus is the common species. All species of syphid preferred plants with flowers or aphids. For example, Sphaerophoria rueppelli, Sphaerophoria scripta, Paragus compeditus, Posthosyrphus latilunulatus, Syritia pipiens preferred plants infested by aphids. Strategies to protect the syrphids and to apply the natural enemies in cotton aphid control in northern Xinjiang were suggested.

Key words: syrphids, species composition, habitat selection, plants characteristics