Abstract: 【Aim】 The Colorado potato beetle, Leptinotarsa decemlineata is an important quarantine pest in China, and it has serious harm to Solanaceae plants. This study aims to clarify the effects of late spring coldness and short-term low temperature on the growth of L. decemlineata population. 【Methods】 L. decemlineata eggs were exposed to low temperature of 8℃ for 1, 3 and 5 d, and those cultured at 27℃ were used as the control, and the egg hatching rate, growth and development of larvae and adult reproduction were investigated. The effects of short-term low temperature on the population growth of Colorado potato beetles were evaluated by population parameters.【Results】 When L. decemlineata eggs were exposed to low temperature of 8℃, the egg duration was significantly prolonged with the treatment time. The egg hatching rates in the treatment groups of 3 d and 5 d were significantly lower than that of the control, and the 1st instar larval duration in these two treatment groups was significantly longer than that of the control. However, the 2nd, 3rd and 4th instar larval and pupal duration was not significantly affected by the low temperature treatment of 8℃. After L. decemlineata eggs were exposed to low temperature of 8℃ for 5 d, the survival rates of the 1st instar larvae and adults were significantly lower than that of the control, but those of the other developmental stages in various treatment groups showed no significant difference. After L. decemlineata eggs were exposed to low temperature of 8℃ for 3 d, the intrinsic rate of increase (r), finite rate of increase (λ), and net reproductive rate (R₀) of population were significantly lower than those of the control and exposed to low temperature for 1 d, but the mean generation time (T) in various treatment groups were not significantly different.【Conclusion】Short-term low temperature stress has adverse effects on the growth and development of L. decemlineata and slows down its population growth.

Key words: Leptinotarsa decemlineata, low temperature, population parameters, developmental duration, survival rate