The Effects of Different Cotton Varieties on the Carmine Spider Mite, Tetranychus cinnabarinus Boisd. (Acari: Tetranychidae)

The aim of this study was to delta differences in resistance to the carmine spider mite, Tetranychus cinnabarinus between cotton varieties grown in different areas. The effects of 8 varieties from several countries cm the development, longevity and fecundity of T-cinnabarinus were investigated in the laboratory. On leaves of the Egyptian cotton, Gossypium vitifolium, variety Giza 75, both females and males required a longer period to complete development than on the G. hirsutum varieties Coker 310 and MCH H. Female mites reared on the variety Coker 310 lived significantly longer and had the longest oviposition period. The largest total progeny per female was observed on the varieties Coker 310 and MCH H, the smallest on the varieties Aleppo 1 and Giza 75. The cotton varieties had no effect on the sex ratio of T. cinnabarinus. In general, the G. hirsutum varieties Coker 310 and MCH 11 appeared to be most supportive for T. cinnabarinus, whereas the G. vitifolium variety Giza 75 clearly showed reduced susceptibility.