低温下光周期诱导半闭弯尾姬蜂蛹休眠研究

Study on photoperiod induction toundevelopment of pupae Diadegma semiclausum Hellen under low temperature

本实验研究目的是在低温下诱导半闭弯尾姬蜂Diadegma semiclausum Hellen休眠,为半闭弯尾姬蜂蜂蛹的保存技术提供科学依据。试验方法在室内温度10℃、设置4个光周期:L∶D=10∶14、L∶D=12∶12、L∶D=14∶10、L∶D=16∶8,观察半闭弯尾姬蜂蛹休眠诱导的光周期反应。结果表明,蛹是半闭弯尾姬蜂休眠的敏感虫态,休眠蛹表现出对光周期的数量反应特征,休眠诱导的临界日长在14-16 h之间。不同光周期具有不同的诱导效果,短光照促进休眠,蛹在光周期为L∶D=10∶14时休眠率最高,达73.03%;光周期为L∶D=16∶8时,则仅为10.67%。半闭弯尾姬蜂感受休眠信号的敏感期为预蛹期,进入休眠,蛹感受休眠信号以后,需要在发育条件中发育到预蛹后期,蛹才能全部进入休眠。将室内诱导的休眠蛹在10℃左右环境条件下冷藏42 d,休眠蛹仍有64.13%可以正常羽化。结论:低温和短光照是诱导该种天敌昆虫休眠的主要因子。

Diadegma semiclausum Hellen overwinters as undevelopment pupae, the undevelopment pupae have order of magnitude characters. Laboratory studies were conducted on certain upsets of biology of Diadegma semiclausum Hellen. Photoperiodic response curve showed that critical day length was between 14 h and 16 h at 10℃ under photoperiod of 10L ： 14D, 12L ： 12D, 14L ： 10D, 16L ： 8D. The emergence rate of the undevelopment cocoons should still reach to 73.03% was exposed to 10L： 14D, and reach to 10. 67% was exposed to 16L ： 81）. Diadegma semiclausum （Hellen） （Hymenoptera： Ichneumonidae） accepted the signal for undevelopment at the pre -pupa stage. All pre -pupae entered undevelopment only if the young larvae had been reared in the temperature and the photoperiod for undevelopment induction till mature pupae. After 42 days cold storage about 10℃, the emergence rate of the undevelopment cocoons could still reach to 64. 13%. So there has two factors played the key role in undevelopment induction, while effect of photoperiod on undevelopment induction depended on temperature. Thus, lower temperature and shorter day length were the major factors to induce undevelopment of the parasitoid.