鸡嗉子榕缩腹榕小蜂触角形态及其感器的性二型

Sexual Dimorphism in Antennal Morphology and Sensilla Ultrastructure of Apocrypta sp.(Hymenoptera:Agaonidae)in Ficus semicordata

使用环境扫描电镜对缩腹榕小蜂雌雄蜂触角及其感器类型、数量、分布等进行了详细的观察,分析了感器的形态性状和生态适应性.缩腹榕小蜂触角具有明显的雌雄二型性,雌蜂触角长862.75±20.65μm,由转节、柄节、梗节和10个鞭小节组成的鞭节构成,分布着毛形感器、刺形感器(Ⅰ型和Ⅱ型)、锥形感器(Ⅰ型)、多孔板形感器(无沟型)、栓锥型乳突状感器、蒲姆氏鬃毛6类7种感器;雄蜂触角大幅度退化,长度仅为345.18±9.44μm,仅有柄节、梗节和1个触角小节构成的鞭节,着生有毛形感器、锥形感器(Ⅱ型)、多孔板形感器(具沟型)、腔锥形感器、蒲姆氏鬃毛5类5种感器.雌蜂触角感器数量明显大于雄蜂,同类感器的长度、分布或其孔密度与雄蜂有着显著的差异,这种适应性进化可能与雌蜂的果外寄主定位和产卵行为有关,雄蜂与果内配偶识别相联系.研究结果将有助于进一步诠释雌雄蜂不同进化压力下的形态分化、繁殖行为和信息利用与分配策略.

Antennae and its sensillum in the female and male Apocrypta sp.were examined by using environmental scanning electron microscope,and then were discussed on the basis of evolutionary adaptation of morphological characteristics.Apocrypta sp.has a typical sex dimorphism on the whole antennae.Antennae of female fig wasps are 862.75±20.65μm in length,and consist of a radicula,scape,pedicel,and flagellum which is composed of 10 flagellomeres.Seven morphological sensillar types were identified in females,including trichoid sensilla,chaetica sensilla(typeⅠandⅡ),basiconic sensilla(typeⅠ),multiporous placoid sensilla(non-grooved types),basiconic capitate peg sensilla,and b9 hm′s bristles.Antennae of male fig wasps are substantially reduced,345.18±9.44μm in length,and comprised of a scape,pedicel and flagellum that contains 1 antennomere.Five sensillar types were found in males,including trichoid sensilla,basiconic sensilla(typeⅡ),multiporous placoid sensilla(grooved types),coeloconic sensilla,and b9 hm′s bristles.The abundance of antennal sensilla of female far exceeded that of males.Significant differences were observed in the sensillar morphology,distribution,or pore density of the same type of antennal sensilla between female and male fig wasps.The pressure-adaptive morphology of the various types of the antennal sensilla demonstrated the positive dependence on the morphological division and ecological adaptation.Due to different ecological functions of females and males,they produced the pressure-adaptive morphologies,which correlated with the oviposition behaviors of females and with the mate choice of males in fig cavity.Our results will facilitate the understanding of the intrinsic relationships between the morphological division,reproductive behavior,and chemical utilization and partition in the sexual selection of fig wasps.