حساسية بعض اصناف القطن للاصابة ببعض الافات الحشرية والاكاروسية في محافظة نينوى

The study showed to testing susceptibility of some cotton varieties Taka 1, Lashata, Nazly 87, Delta pine 50, Stonvile 474, Stonvile 887 at kuba region in Ninevah Governorate during the year 2005 to infection with some insects and mites was outlined the cotton varieties was infected in different degrees with white fly Bemisia tabaci Gen. Aphis gossypii Glov., Empoasca spp., Thrips tabaci Lind and Tetranychus urticae koch. The general mean numbers of these pests on varieties Taka 1, Lashata, Nazly 87, Delta pine 50, Stonvile 474, Stonvile 887 reached 3.26, 3.0, 2.25, 2.82, 3.34, 3.68 individual / 20 leaves respectively. The number of white fly was the highest significantly 6.67 individual / 20 leaves among other pests, while the mean number of aphid was the lowest mean 1.37 individual / 20 leaves. The variety Taka1 was the lowest sensitivity with each of leafhoppers and cotton aphid, while the variety Nazly 87 was the lowest sensitivity with thrips and white fly. The Deltapine variety was the lowest sensitivity with infection of red mite and the variety of stonvile 474 was the lowest sensitivity with infection of cotton aphid which reached 1.0 and to all their varieties. On other side the higher sensitivity of cotton varieties with infection by cotton thrips, leaf hoppers, cotton aphid, white fly, and red mite was stonvile 887, Delta pine 50, stonvile 887, Taka 1, Lashata respectively which reached 2.75, 2.15, 2.33, 1.89, 3.12, respectively. The statistical analysis showed that there are a significant differences at probability 5 % in the mean numbers of pests on cotton varieties according to the date of samples.