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The cotton aphid, Aphis gossypii Glover (Hemiptera: Aphididae) is a polyphagous pest which spread over more than 900 plant species in tropical, subtropical and temperate zones. High population level of this pest makes it unavoidable to struggle in the early period in cotton producing areas. Therefore at first, determination of the varieties on which the insect have relatively less reproductive capacity is important for the implementation of integrated pest management programs with less risk for the environment and human health. The study determined some life table parameters of the pest on 6 different cotton varieties including Carmen, Gloria, GSN-12, Flash, Ozbek-100, and ST-373, which are widely used in the Gediz Basin (Aydin, Denizli, Izmir and Manisa). As a result, the shortest development time was found on Ozbek-100 variety with 5.50 days and the longest development time on GSN-12 variety with 6.62 days. Also, the highest total fecundity per female was obtained on Carmen variety with 27.12 nymphs/female, and the lowest total fecundity per female on GSN-12 variety with 15.69 nymphs/female. The intrinsic rates of increase (r(m)) of the pest on these cotton varieties were computed as 0.37, 0.37, 0.27, 0.41, 0.43, and 0.30 females/female/day. It was determined that the intrinsic rates of the aphid on GSN-12 and ST-373 varieties were less according to those on other cotton varieties. Feeding of the aphid is hindered on these cotton varieties because both of them have hairy leaf-structure and therefore, the intrinsic rate of the aphid is reduced. The preference of these varieties with high productivity, and earliness features in cotton producing areas will raise the implementation chance of environmentally friendly integrated pest management programs by keeping at relatively lower levels of the aphid population. |
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