《环境昆虫学报》

柑橘大实蝇Bactrocera minax（Enderlein），是柑橘的重要害虫。本研究基于光学、扫描电镜、X射线CT，对其雄虫外生殖器的形态结构、阳茎长度和雌虫泄殖腔到受精囊的长度、以及雌雄虫交配过程中的夹持状态和雄虫阳茎冠到达雌虫阴道位置的观察和测量。结果表明，柑橘大实蝇雄性外生殖器是由阳茎（阳茎管和阳茎冠）、生殖突（阳茎内突和生殖环）和抱握器（背刺突和抱器）这3个部分组成。阳茎管是长而弯曲的双套管结构（向腹面卷曲），外管即阳茎管，内含1条输精管（内管），阳茎管腹面褶皱，骨化程度低，背面平坦（中间有沟），骨化程度较高，既可以弯曲折叠又可以变直。休息时，阳茎蜷曲，大部分隐藏在第5腹节内。阳茎冠由生殖杆、阳茎冠体（基囊、喇叭口、裂口和骨化体）组成，精子出口位于阳茎冠顶部喇叭口内和基囊前端的阳茎冠体上的裂口内。成虫交配时，雄虫抱握器夹持住雌虫产卵针背片端部，阳茎能够到达的最远处为雌虫布氏交配囊。雌虫从泄殖腔口至受精囊长度（21.64 ± 0.59 mm）远大于雄虫阳茎的长度（9.21 ± 0.25 mm），这表明雄虫的阳茎不能到达雌虫的受精囊，雌性可以通过控制精子是否进入受精囊来控制受精。因此，雌成虫拥有最终的授精控制权。这些结构或组织经过进化，从而适应其阳茎的运动、交配等行为活动。为理解昆虫繁殖生理、进化和多样性，昆虫交配、阳茎运动等行为机制提供理论基础。

英文摘要:

The Chinese citrus fly, Bactrocera minax (Enderlein) (Diptera: Tephritidae), is an important pest of citrus crops. In this paper, morphological characteristics of the male external genitalia, the length of the aedeagus, the length from the female cloaca to the spermatheca, as well as the clamping characteristics of the male and female, the male’s distiphallus reaching the position of the female’s vagina during mating of B. minax, were observed and measured on optical microscopy, scanning electron microscopy (SEM) and three-dimensional X-ray microscopy (X-ray CT). The results showed that the male genitalia of B. minax was composed of aedeagus (phallus and distiphallus), genital apodeme (fultella and genital ring) and clasper (surstylus and claspette). The phallus was a long and curved double-pipe structure (bending to the ventral surface), the outer tube was the phallus and contained an ejaculatory duct (inner tube). The phallus had a low degree of sclerotization due to its fold on the abdomen, and the back was flat (with a groove in the middle), with a high degree of sclerotization, which can be both bent, folded and straightened. When the male rested, the aedeagus curled up, most of which was hidden in the fifth abdominal segment. During mating, the male clasper clamped the distal of the female tergite, and the farthest distance that the aedeagus reached through the cloaca was the female bursa copulatrix. The distiphallus was composed of the genital rod and the distiphallus body (basal sac, trumpet, split and sclerotization area). The sperm outlet was located in the trumpet at the top of the distiphallus and the split on the distiphallus body at the front end of the basal sac. The length from the cloacal opening to the spermatheca of female adult B. minax (21.64 ± 0.59 mm) was much longer than that of aedeagus of male adult (9.21 ± 0.25 mm), which indicated that male aedeagus can't reach the spermatheca of female, and female can control fertilization by controlling whether sperm enters the spermatheca. It further showed that female adults had the ultimate control over fertilization. These structures or tissues had evolved to adapt to the movement, mating and other behavioral activities of the aedeagus. This study will provide a theoretical basis for understanding the reproductive physiology, evolution and diversity of insects as well as the insect behavioral mechanisms of mating and aedeagus movement.

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