低温贮藏对半闭弯尾姬蜂蛹和成虫生长发育的影响

半闭弯尾姬蜂是小菜蛾幼虫的优势寄生蜂，低温贮藏是实现半闭弯尾姬蜂规模化生产和应用的重要环节。本文研究在4℃低温条件下，蛹和成虫贮藏5、10、15、20、25、30 d对半闭弯尾姬蜂生长发育的影响，不处理为对照。结果表明：随着蛹期低温贮藏时间的延长，成虫羽化率、寄生率逐渐降低，蛹贮藏5、10 d对成虫的羽化率及寄生率较高，分别在81.50%～83.50%和38.43%～39.02%，贮藏15～30 d后成虫的羽化率和寄生率显著低于对照；随着成虫低温贮藏时间的延长，其存活率、寄生率及其子代羽化率逐渐降低，成虫低温贮藏5 d对其存活率、寄生率及其子代羽化率较高，分别为95.75%、38.05%、86.00%，贮藏10～25 d后成虫的存活率、寄生率及其子代羽化率显著低于对照，贮藏30 d后成虫存活率最低，为9.67%，不能寄生。本文研究表明，半闭弯尾姬蜂在繁殖和田间释放过程中，蛹低温贮藏10 d内，成虫低温贮藏5 d内较理想。

Effects of Low Temperature Storage on the Growth and Development of Pupae and Adults of Diadegma semiclausum

Diadegma semiclausum Hellen is a dominant parasitic wasp of Plutella xylostella Linnaeus. Cold storage has been proved to be important in mass production and application of natural enemies. This study measured the effects of cold storage of pupae and adults at 4℃ for 5, 10, 15, 20, 25, 30 days on the growth and development of D. semiclausum, the insects not exposed to low temperature were used as the control. The results showed that the emergence rate and parasitism rate of the wasps resulting from the stored pupae gradually decreased with the extension of low temperature storage duration, which were 81.50%-83.50% and 38.43%-39.02%, respectively, for storage of 5 and 10 days and were significantly lower for storage of 15-30 days than the counterparts of the control. When the adults were stored, the survival rate, parasitism rate, and emergence rate of offspring gradually decreased with the extension of low temperature storage duration, which were 95.75%, 38.05%, and 86.00%, respectively, for storage of 5 days, and were significantly lower for storage of 10-25 days than the counterparts of the control. The survival rate decreased to the lowest of 9.67% and no parasitism occurred when the adults were stored for 30 days. These results show that the ideal conditions for low temperature storage of D. semiclausum are 10 days for pupae and 5 days for adults at 4℃.