Effects of Temperature on Experimental Population of Chilocorus kuwanae Silvestri

The developmental rates of Chilocorus kuwanae Silvestri were determined under seven constant temperatures,and the threshold temperature of development and effective accumulative temperature of each stage of the ladybeetle was also ascertained.Relationships between developmental rate and temperature could be finely fitted with the model proposed by Wang Rusong et al.(1982).From the model,the highest critical temperatures of development,lowest critical temperatures of development and optimum temperatures of development were estimated to be 10.42-13.01 ℃,33.52-37.03 ℃ and 24.99-30.12 ℃ respectively.Egg stage exhibited the highest ability to emdure changes in temperature,and the 4th-instar displayed the lowest ability.Temperature could obviously affect the survival rate and the type of survival curve of C.kuwanae.Favourable temperature range for development of the ladybeetle was 22-31 ℃.Survival rates in this range were quite similar,and within 28-31 ℃ survival rates were highest.In the paper, we discussed the following topics:the advantages of the model offered by Wang Rusong et al.(1982) over the Logistic equation,possible relationship between the threshold temperature of development and the lowest critical temperature of development,and the effect on explaining the contributing factor of geological distribution of C.kuwanae in Guizhou with results of this research.