酪蝇的羽化节律和交配行为

Timing of emergence and mating of Piophila casei(Diptera: Piophilidae)

【目的】为了明确酪蝇Piophila casei的羽化节律和交配行为,为深入研究酪蝇的性信息素打下基础。【方法】在室内条件[温度(27±1)℃,光周期L︰D=14︰10]下观察了酪蝇的羽化节律和交配行为。【结果】结果表明,化蛹后第8天成虫羽化最多,羽化高峰期出现在由暗期进入光期的前后,雄虫略早于雌虫羽化。观察结果表明,当雄虫接近蛹壳时会表现出"触摸"、"经过"、"扑"、"抱握"等动作,而雌虫仅有"触摸"、"抱握"的动作。当遇到同性成虫或者已交配雌虫时,雄虫会"追逐"对方,当接触到对方时雄虫会表现出"抱握"、"触摸"动作以进行识别,被识别雄虫会"翘起腹部末端"使对方离开,已交配雌虫则猛烈"摆动身体"使对方离开。当遇到处女雌虫时,雄虫跳跃到雌虫背上迅速进行交配。雌虫羽化后1 min即可交配,雄虫羽化后30 min可交配,交配平均持续时间10 min。雄虫间会有交配竞争行为发生,后来者会跳跃到先来者背上,向下弯曲腹部试图越过先来者与雌虫交配。【结论】酪蝇的羽化高峰出现在进入光期前后。成虫对蛹壳有显著趋性,雄虫主动追逐识别异性,较雌虫表现出更强烈的交配欲望。

[Objectives] To determine the timing of emergence and mating of Piophila casei（Diptera： Piophilidae）, and thereby provide a reference for further research on the sex pheromones of this species. [Methods] The emergence and mating behavior of P. casei were investigated under laboratory conditions [（27 ±1）℃, L︰D = 14︰10]. [Results] The peak of adult emergence occurred in the 8th day of the pupal stage, and peaked before and after the scotophase to the photophase, with females emerging slightly later than males. The behavior of males and females, differed; males engaged in touching, passing, rushing and clasping, whereas females only engaged in touching and clasping. When males encountered other males or mated females, they would chase both of them, and identify them by clasping and touching. Males attempted to displace other males by lifting the end of their abdomen whereas mated females attempted to displace additonal males by swinging their body vigorously. When males encountered virgin females, they quickly jumped onto the female＇s back to mate; females could mate just 1 min after emergence but male could not mate until 30 min after emergence. Mating duration was mainly about 10 min. There was competition between males to mate, males encountering a mating pair would jump on their rivals back and bend down its abdomen while trying to reach over it to mate with the female. [Conclusion] Emergence peaked from before, and after, the scotophase to the photophase. P. casei adults were significantly attracted to new puparia, males recognized and pursued females, and the mating urge of males was much stronger than females.