A.H. EL-HENEIDY, YAJ-IIA H.FAYAD AND MONA A.SHOEB
Dept .of Biological Control, Plant Protection Institute, ARC, Giza , Egypt

ABSTRACT

The present study was carried out to evaluate the effect of chemical treatments on aphids and their natural enemies in wheat fields during 1990-1991 planting season at Sohag Govemoraze (upper Egypt) Twos districts ; El - Maragha and Shandaweel were selected for this study Rate of aplds infestation , numbers of predators and percentage of parasitism were estimated weeldy aflover the season in the two locations El - Maragha field was treated three times with insecticides by laze February, while Shandaweel fields was treated only once early in the season . Obtained data showed that in spite of the frequent spray at El-Maragha field,aphid infestation lasted lenger than that of Shandaweel and continued relatively higher throu!hout the season Sharp decline in the number of predators (40-48%) and in the percentage of parasitism (66%) was observed after the insecticidal application, while a gradual increase in the number of predators was occurred towards the end of the season Shandaweel field Therefore an integrated aphid control programme in wheat fields considering the positive role of parasitoids and predators rather than dependance on chemical control should be developed.

Key Words: Wheat, Aphids, Parasitoids, Predators, Insecticides.