Influence of temperature on development and reproduction of experimental populations of the Colorado potato beetle,Leptinotarsa decemlineata(Say) (Coleoptera:Chrysomelidae)

To research the influence of temperature on the development and reproduction of experimental populations of the Colorado potato beetle,Leptinotarsa decemlineata (Say),and then provide some basic data for the control and prediction of pest,the development and reproduction of every stage of Leptinotarsa decemlineata (Say) were observed at five temperatures (15℃,19℃,23℃,27℃ and 31℃) in the laboratory. The developmental threshold temperature and effective accumulated temperature of different stages of the Colorado potato beetle were calculated. The results showed that the developmental rate of the Colorado potato beetle increased with the rise of temperature from 15℃ to 31℃. The generation survival rate of the Colorado potato beetle decreased in the order of 27℃23℃19℃31℃15℃,suggesting that excessively high or low temperature was unfavorable to the survival. The developmental threshold temperatures required for egg stage,1st instar,2nd instar,3rd instar,4th instar,whole larval stage,pupal stage and egg-adult period were 9.14,10.50,8.17,10.28,9.04,9.59,10.23 and 10.90℃,while the effective accumulated temperatures were 73.26,43.22,39.23,34.05,161.97,273.02,100.38 and 542.58 degree-days,respectively. It is so concluded that the influence of temperature on the developmental duration,survival rate and reproduction of experimental populations of the Colorado potato beetle was remarkable.