低温20℃对意大利蜜蜂未受精卵发育的影响

【目的】蜜蜂是狭温性昆虫的代表,低温对意大利蜜蜂Apis mellifera ligustica未受精卵发育的影响尚不清楚。【方法】将0~66 h卵龄的意大利蜜蜂未受精卵放置在20℃下分别处理梯度时间。【结果】低温20℃导致意大利蜜蜂未受精卵的孵化率下降,发育历期延长。0、3、6、9 h卵龄的卵对低温极敏感,处理0.5 h孵化率下降,处理4.0 h,全部死亡;发育12、24 h的卵在低温中处理4.0 h不受影响(P>0.05),处理12.0 h,全部死亡;发育36 h以上的卵则较耐低温,处理12.0 h无影响(P>0.05),处理36.0 h,各卵龄没有全部死亡,其中最低的孵化率为25.4%。12~66 h的卵在低温20℃下的发育历期(y)与处理时间(x)呈现显著的线性回归关系,发育历期延长的时间约等于处理时间长。【结论】意大利蜜蜂未受精卵对低温20℃的敏感性与卵龄关系密切,低卵龄的意大利蜜蜂未受精卵比高卵龄更易受低温影响。这些结果为深入研究温度对蜜蜂胚胎发育影响的机制奠定基础,也为蜜蜂的科学饲养提供了理论依据。

Effects of low temperature on unfertilized honeybee (Apis mellifera ligustica) eggs

Objectives] Although the honeybee is known to be a stenothermal insects the effect of low temperature on the hatching of haploid Apis mellifera ligustica eggs remains unclear. Methods] Haploid eggs of different ages were subjected to 20℃ for a different number of hours. Results] The hatching rate and developmental duration of unfertilized eggs were significantly affected by cold exposure. Unfertilized eggs between 0 and 9 h of age were more cold-sensitive than older eggs, being significantly affected by the minimal duration of 0.5 h cold exposure and with 100% mortality when exposed to cold for more than 4.0 h. In contrast, eggs between 12 and 24 h, and those >36 h old, showed no negative effects after 4.0 h and 12.0 h cold exposure, respectively. A simulation analysis showed that egg hatching duration was highly correlated with the duration of cold exposure, and that the increase in time until hatching was approximately equal to the duration of cold exposure. Conclusion] Sensitivity to cold depends on how recently unfertilized eggs had been laid. Newly laid eggs were more susceptible to low temperatures than older eggs. These results will be helpful for further study of how temperature effects honeybee embryo development, and provides a scientific basis for novel beekeeping strategies.