Seasonal changes in the supercooling point of overwintering eggs of Locusta migratoria
JING Xiao-Hong, KANG Le **(State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, the Chinese Academy of Sciences, Beijing 100080, China)
The supercooling points (SCP) of overwintering eggs of the migratory locust were measured monthly with a thermocouple. The results show that the distribution of egg SCP values mainly formed two peaks, one around -25℃, and the other around -10℃. The SCP prorate between the two peaks differed markedly with seasonal changes in climate. In mid-winter, SCP values were about -25℃, and the minimum value also reached its minimum, in contrast they were about -10℃ in spring and summer,and the maximum value become higher. This phenomenon to some extent explains the ability of the migratory locust to withstand low temperature.