葱兰夜蛾雌雄鉴定和交配行为

Distinguishing the sexes and reproductive behavior of Brithys crini(Lepidoptera:Noctuidae)

【目的】建立一种准确快速区分葱兰夜蛾Brithyscrini蛹和成虫性别的方法,掌握葱兰夜蛾的生殖行为节律,为进一步开展该虫性信息素的鉴定提供科学指导。【方法】在室内饲养观察并测量蛹的长、宽和体重3个指标,确定最佳性别区分方法;研究不同日龄下成虫交配行为规律,以及交配史对成虫产卵、寿命的影响。【结果】葱兰夜蛾雌雄蛹差异明显,雌蛹生殖孔位于第8和第9腹节,第8腹节不愈合;雄蛹生殖孔仅位于第9腹节上,且生殖孔两侧有明显的半圆形突起。雌蛾腹部较为粗大,末端附着的黑色毛簇短而少;雄蛾腹部狭长,其末端附着有一圈黑色长毛簇。交配行为开始于暗期4 h后,6–9 h达到高峰,雌雄成虫交尾率为44.00%。1日龄雌蛾即可进行交尾且生殖行为最活跃,交尾率、交尾时长均与日龄呈负相关关系。交尾雌蛾的产卵率和产卵量都大于未交尾雌蛾。相同生殖状态下雌虫平均寿命大于雄虫,但是不同处理雌雄成虫的寿命无显著性差异。【结论】葱兰夜蛾可以通过蛹的生殖孔和成虫的腹部末端差异区分。交配行为的变化规律与成虫日龄密切相关,两者间具有一定时间上的协调性。交配行为显著影响雌蛾的产卵量(P<0.05),对成虫寿命也有一定影响。

[Objectives]To develop a way of accurately,and quickly,distinguishing the sex of Brithys crini pupae and adults,and determine the daily timing of reproductive behavior in this pest.[Methods]The length,width and weight of pupae were measured and the sex of emergent adults recorded.In addition,the courtship and mating behavior of adults of different ages were studied.[Results]Female pupae have genital pores on the 8th and 9th ventral segments,and the 8th ventral segment does not heal.The genital pore of male pupae is located on the 9th abdominal segment,and there are obvious semicircular protuberances on either side of the genital pore.Courtship and mating behavior occurred during the dark phase of the photoperiod.Female courtship behavior began 2 hours after dark,and peaked 4 to 8 hours after dark.Females began mating 4 hours after dark,and mating reached its peak 6 to 9 hours after dark.Females began to display courtship behavior at 1 day of age.The older the adult,the lower the mating rate but the longer the mating time.Females could lay eggs in different reproductive states.The life span of adult females was longer than that of males in the same reproductive state.[Conclusion]The sex identification of B.crini pupae could be distinguished by the difference of genital pore.The courtship and mating behaviors are closely related to the age of adults,and there is a certain time coordination between them.The mating behavior could significantly affect the number of eggs and longevity of adults.