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Sudan Journal of Agricultural Research

Population dynamics of the wheat aphid, Schizaphis graminum, (Rondani) (Homoptera, Aphididae)and its natural enemies in the field


Hassan Orner Kannan^l


Abstract:

The greenbug S. graminum, is the most important aphid on wheat and is responsible for most of the economic damage inflicted on the crop. Chemical insecticides, the only tool used, were normally applied to control the aphid when sprayable levels were attained. However, total reliance on a single control measure invites vulnerability to a disaster. The present study was conducted in Rahad Scheme during seasons 1989/90-1992/93 to monitor and quantify the natural buildup of the wheat aphid and its natural enemies. The investigation revealed that S. graminum was the most abundant and most important aphid on wheat, and its occurrence interfered with grain formation and filling. The natural enemies encountered
preying on aphids were; chrysopids, coccinellids and syrphids, the first of these being the most important and doninant predators. The lacewings, Chrysoperla pudica and C. zastrowi were reported early in the season and played a remarkable role in suppressing aphid populations and maintaining them beyond the economic injury level.

Keywords:

Sudan Journal of Agricultural Research Vol. 2(1999) PP. 65-68