一种斑翅果蝇寄生蜂的交配行为观察及雄虫交配次数对繁殖的影响

Mating behavior of Trichopria drosophilae and the effect of male mating frequency on the production of female offspring

【目的】明确一种斑翅果蝇寄生蜂Trichopria drosophilae的交配行为以及雌雄蜂的交配次数对后代的影响。【方法】在室内对斑翅果蝇寄生蜂的交配行为进行观察,记录该蜂在交配行为中所出现的求偶行为、交尾前期行为、交尾行为和交尾完毕的动作及持续时间。测定寄生蜂各交配次数下的雌蜂寿命、后代出蜂总量和后代性比。【结果】寄生蜂的交配过程包括以下几个阶段:求偶,雄蜂逐渐靠近雌虫、追逐雌蜂并震动翅膀,直至爬上雌虫背部整个过程持续(50.47±85.01)s。交尾前期,雄虫头部从雌蜂的两触角中间伸出,并将触角从雌虫触角两侧向中间有规律的触碰雌虫触角,直至雌蜂打开生殖孔,整个过程持续(43.73±13.97)s。交尾,雄蜂将雄性交配器插入雌性生殖孔整个过程持续(36.28±11.03)s。交尾后期,雌虫左右甩动腹部2~3次,主动与雄虫分离整个过程持续(8.95±3.40)s。观察结果显示,雌虫一生只能交配一次,雄蜂一生交配次数在(16.54±1.37)次,最多达到19次(N=10),雄虫的交配次数对与之交配的雌蜂的寿命和后代总量无显著影响。雄蜂的交配次数对雌性后代的性比有显著影响。【结论】该寄生蜂的交配过程主要分为雄虫求偶、交尾前期、交尾、交尾后期等阶段。求偶和交尾前期阶段主要行为是雄虫追逐雌蜂、爬上雌虫背部并用触角摩擦雌虫触角。交尾阶段主要行为是雄蜂交配器插入雌性生殖孔。交尾后期主要行为是雌蜂将雄蜂甩开,是雌虫唯一主动发起的行为。随着雄蜂交配次数增加,雌蜂后代雌/雄性比降低。

[Objectives] he mating behavior of the parasitic wasp Trichopria drosophilae and the effect of the frequency of mating of male and female wasps on offspring sex ratio was determined. [Methods] The mating behavior of T. drosophilae was observed in a laboratory, and the various stages of this, including pursuing, courtship, early mating period, mating, as well as the duration of mating, were recorded. Furthermore, the effect of the number of mating events on the number of offspring and the life span of female adults was investigated. [Results] The mating behavior of T. drosophilae included the following stages： Pursuing （95.45 ± 71.23） s, males gradually walking up to females; Courtship （50.47 ± 85.01） s, males shaking their wings and beginning to chase and climb onto the backs of females; early mating period, in which the male＇s head extends from between the female＇s antennae and the male＇s antennae touch the mid-portion of the female＇s antennae on both sides; mating（36.28 ± 11.03） s, the males copulatory apparatus is inserted into the females genital pore; late mating （8.95 ± 3.40） s, females drive off males by vigorously swinging their abdomen. The mating frequency of males was significantly higher than that of females; females only mate once in their lifetime whereas males can mate up to 19 （16.54 ± 1.37） times （n=10）. [Conclusion] The mating behavior of T. drosophilae can be divided into distinct stages. The pursuing stage is the longest and is initiated by males which also are the most active sex during the courtship stage. The shortest stage is the late mating stage which is the only stage initiated by females. Males that mate more often produce noticeably fewer female offspring.