Effect of Temperature on Development and Fecundity of Cotton Aphid(Aphis gossypii)

The development,mortality rate and fecundity of Aphis gossypii Glover(Hom.,Aphididae) were evaluated on detached cotton leaves at six high constant temperature(26℃,28℃,30℃,32℃,34℃,36℃) in laboratory.The developmental periods of the immature stage ranged from 5.9 days at 26℃ to 4.4 days at 34℃.A constant temperature of 36℃ was lethal to the immature stage of Aphis gossypii and mortality rate was up to 99% in four days.The mortality rate were estimated to be 17.5%,25.0%,25.5%,22.6% and 22.0% at 26℃,28℃,30℃,32℃,34℃.The age-specific fecundity and net reproductive number were at peak numbers at 28℃ with numbers of 14.0 and 53.0.The intrinsic rate of increase were estimated to be 0.304,0.398,0.385,0.245 and 0.124 at five temperatures. The optimum temperature for development was 29.0℃ and lethal temperature of cotton Aphid was 35.5℃.The optimum temperature for fecundity was 28.8℃ and lethal temperature for fecundity of cotton Aphid was 34.9 ℃ based on fitting model.Summer aphid had relatively great reproduction from 28℃ to 30℃,and seriously damaged cotton growth.