环境温度对马尾松毛虫发育与存活的影响

通过模拟马尾松毛虫2、3代发生区内第2代幼虫发生期温度的变化，进行了高温、常温和低温3组变温试验.结果表明，在相同光照条件下，3龄以前的马尾松毛虫幼虫死亡率明显不同.马尾松毛虫幼虫死亡率在长光周处理内低温组为25.55%，常温组为55.13%，高温组为58.23%；在短光周处理内低温组为32.67%，常温组为64.67%，高温组为94.32%,说明高温是影响马尾松毛虫低龄幼虫死亡的主要原因.高温还影响马尾松毛虫幼虫的滞育.在相同短光周条件下，幼虫孵出后20 d，高温组幼虫40%发育为5龄，而低温组和常温组全部滞育；幼虫孵出后48 d，高温组全部结茧，而低温组和常温组仍全部滞育.试验证明，马尾松毛虫在第2代幼虫孵出后20 d内如遇连续高温环境，即使在短光周条件下，幼虫也不会滞育.

Effects of environmental temperature on Dendrolimus punctatus development and survival

In a simulation test, three treatments of low, normal and high temperature were designed to examine the effects of environmental fluctuant temperature on the development and survival of second generation Dendrolimus punctatus larvae. The results showed that under different temperature but same light and dark cycle, the mortality of 1st- 3rd instar was apparently different. Under long photophase, the larval mortality of 1st- 3rd instar was 25.55 %, 55.13% and 58.23% at low, normal and high temperature, while under short photophase, the mortality was 32.67 %, 64.67 % and 94.32 %, respectively. High temperature resulted in the diapause of larvae. Under the same short photophase, the larvae exposed to high temperature could develop to 5th instar by 40%, while those exposed to normal and low temperature kept diapause, and could not develop to 5th instar after 20 days. After 48 days, the larvae exposed to high temperature became cocoons, while those exposed to normal and low temperature still diapaused. It was suggested that if the second generation larvae of D. punctatus encountered consecutive high temperature, most of them could develop to third generation.