Abstract

Several studies were conducted to evaluate the influence of some nutritional and biochemical characters of three cotton cultivars on the biological performance of the two spotted spider mite Tetranuchus urticae Koch. and the predators Stethorus gilvifrons(Muls.) and Scolothrips sexmaculatus (Pergs.) .Results indicated that the cotton cultivars had significant difference in their content of nutritional and biochemical materials which where also influenced by the growing stages of the crop. Lashata cultivars showed the highest values of PH ,nitrogen, protein content, total soluble solids, and sucrose .While, the lowest values of phosphorus and potassium were also recorded for this cultivar These differences showed significant effect on the biological performance of the two spotted spider mite. The shortest development time for immature stages and higher survival percentages were 10.2 and 91.2% respectively recorded for individuals reared on lashsata cultivar. While the longest development time and lower survival rate were 7.8 days , 67.4% recorded for mite fed on Ashur cultivar respectively. The cultivar Lashata was the most suitable host for mite adults. Female and male longevity were 11.4 and 5.7 days respectively. Same trend was observed in term of the influence of cotton cultivars on mite predators, Stethorus gilvifrons and Scolothrips sexmaculatus. Lashata cultivar was the most suitable host plant for both predators , while Ashur cultivar was the least supportive host in term of the relation of the nutrient and biochemical characters to the biological performance of predators. Therefore ,these predators should be taken in consideration in any management practices in order to secure better production of the available cotton cultivars.

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The article was added to IASJ on 2012-05-22

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