高温胁迫六斑月瓢虫对其生物学特性及其捕食作用的影响

Effects of high temperature stress on the biology and predatory behavior of Menochilus sexmaculates

【目的】为明确高温胁迫下对六斑月瓢虫Menochilus sexmaculates的生物学特性及其捕食作用的影响。【方法】在35℃高温处理不同时长(3、6、9 h)的胁迫下,探究六斑月瓢虫的生长发育、存活、繁殖力和虫态特征的变化规律,同时评估了其对豆蚜Aphis craccivora的捕食功能与寻找效应。【结果】与25℃饲喂相比,高温胁迫下六斑月瓢虫的幼期历期和雌雄虫寿命随着胁迫时长的增加而缩短,且高温胁迫不同程度降低了六斑月瓢虫的产卵量、卵孵化率和幼期存活率,而对六斑月瓢虫4龄幼虫、成虫的体长和虫重无影响。通过研究捕食作用,与常温25℃相比,35℃高温胁迫在一定程度上促进了六斑月瓢虫对蚜虫的捕食效能,其中在高温胁迫9 h后,其捕食能力(a'/Th)和寻找效应(S)均高于3 h和6 h的。【结论】高温对六斑月瓢虫的生物学特性产生负面的影响,而对其捕食活动具有正面的影响。研究结果为六斑月瓢虫的生物防治提供了科学依据,同时为全球气候变暖下天敌昆虫的保护与利用奠定了基础数据。

[Objectives]To clarify the influence of exposure to high temperature on the biology and predatory behavior of the ladybug Menochilus sexmaculates.[Methods]Ladybugs were exposed to 35℃for 3,6 and 9 h after which their development,survival,fecundity,morphological characteristics and predation on Aphis craccivora,were measured and compared.[Results]The results revealed that,compared to ladybugs kept at 25℃,exposure to 35℃decreased adult longevity,egg production,immature survival and hatching rate,but had no effect on body length or weight.Moreover,the predation capacity(a'/Th)and search efficiency(S)of M.sexmaculates with respect to A.craccivora were higher at 35℃than 25℃,in particular after 6 and 9 h at 35℃.[Conclusion]High temperature appears to have an adverse impact on M.sexmaculates but also to some extent increases its capacity to prey on A.craccivora.These findings provide a scientific basis for using M.sexmaculates as a biological control and increases understanding of the effects of global-warming on the natural enemies of pest insects.