斜纹夜蛾的性选择行为

【目的】为了解斜纹夜蛾Spodoptera litura Fabricius体重、日龄、交配经历及形态特征对其性选择行为的影响。【方法】本实验通过标记成虫后,采用观察记录的方法对其进行探究。【结果】斜纹夜蛾雌虫的体重对雄虫的性选择影响比较明显,体重较大雄虫优先选择体重较小的雌虫(71.43%),而体重较小雄虫喜欢选择体重较大的雌虫(72.00%)。体重较大和体重较小的雄虫都能获得体重较大雌虫的交配选择,但是体重较大者被选择的机会更大(70.00%),体重较小的雄虫不能获得体重较小雌虫的选择。雄虫仅选择1日龄的雌虫,而雌虫偏向选择3日龄和5日龄雄虫。交配经历影响斜纹夜蛾的性选择,未交配的雄虫优先选择未交配的雌虫(86.67%),但未交配的雌虫则优先选择已交配的雄虫(66.67%)。雄虫的形态特征(体长、翅展、腹长、复眼间距和触角长)对雌虫性选择有较明显的影响,但雌虫的形态特征除翅展的大小外,其体长、腹长、复眼间距和触角长等形态特征在雄虫选择进行交配中的作用不大。【结论】体重、日龄、交配经历及形态特征都能不同程度影响斜纹夜蛾的性选择行为。

Sexual selection in Spodoptera litura Fabricius (Lepidoptera：Noctuidae)

Objectives] To understand the effect of body weight, age, mating experience and other morphological characteristics of Spodoptera litura Fabricius on mate choice and mating success. Methods] Adults were weighed and marked so that individual mating success could be observed and recorded. Results] The majority (71.43%) of heavier males preferred to mate with smaller females, and vice versa (72.00%). Females mated with both heavier and lighter males, but heavier males had a greater chance (70.00%) of mating. Male S. litura only mated with one-day-old females but females preferred to mate with three, or five-day old, males. Mating experience influences sexual selection in S. litura; most (86.67%) virgin males mated with virgin females, whereas most (66.67%) virgin females mated with non-virgin males. The morphological characteristics of males had a more obvious effect on female mate choice. However, females’ morphological characteristics, including wing size, body length, abdomen length, eye spacing and antennae length, played a minor role in influencing male choice. Conclusion] Weight, age, mating experience, and morphological characteristics, of S. litura all influence mate choice in this species to different degrees.