| Population amounts and non-preference of cotton aphid(Aphis gossypii Glover) were investigated in different cotton varieties.The data were analyzed using Duncan's multiple test.The result showed that there was obvious difference in non-preference of the winged aphids to cotton varieties.The aphids weren't attracted evidently by Xuzhou 142 and E'mian No.6,but were attracted strongly by Xingaokang No.5,33B and SGK insect-resistant cotton.The population amounts of aphid on the Xuzhou142 and E'mian No.6 were lower than those of on Xingaokang No.5,33B and SGK insect-resistant cotton.The amounts of aphid on different varieties were all increased with the growth of cotton during the investigated period,and they were increased more quickly on Xingaokang No.5,33B and SGK insect-resistant cotton than other cotton varieties.Damage index on 33B,Xingaokang No.5 and SGK insect-resistant cotton was higher than on other experimental cotton varieties at the same growth stage of cotton. |