No abstract

Wheat, Triticum aestivum L. is an important cereal crops in Egypt. Corn leaf aphid, (Rhopalosiphum maidis Fitch) a species of aphid attacks plenty of the Gramineae plants and most cereal crops. The biological attributes of R. maidis reared on the nine wheat varieties, namely, Sids-12, Sids-14, Gimmiza-11, Giza-171, Misr-2, Bani suif-5, Bani suif-6, Suhag-4 and Suhag-5 were studied. The wheat varieties differed significantly in the duration of 1 st , 2 nd , 3 rd and 4 th nymphal instars. Wheat varieties effect significantly on the total developmental time of nymphal stage. The highest developmental time was recorded on Sids-14 variety with 5.80 days. On the other hand, data showed no significant differences between the nine wheat varieties in reproductive period. Bani suif-5 variety recorded the highest average number 11.90 days. On the other side, the aphids reared on Gimmiza-11 variety recorded the lowest average number 9.25 days. Data showed that the total number of offspring per female and mean number of offspring/day affected significantly by wheat varieties. There are a significant differences in longevity and generation period of R. miadis reared on the wheat varieties examined.