佩妃延腹榕小蜂的产卵行为

榕树与传粉榕小蜂之间的互惠共生关系是协同进化研究领域中的热点之一。榕树除了与传粉榕小蜂共生外，它还为许多非传粉榕小蜂提供食物和生境。佩妃延腹榕小蜂Philotrypesis pilosa Mayr腹部第8～9节背板极度延伸，形似长长的产卵鞘，其后更长的才是真正的产卵鞘。它将产卵针刺入榕果的果壁，产卵于果内。该蜂是对叶榕Ficus hispida L. 的传粉榕小蜂Ceratosolen solmsi （Mayr）的盗食性寄生蜂。我们利用数码照相机记录了佩妃延腹榕小蜂产卵的全过程，详细描述了其产卵行为。发现了前人没有发现的下列行为特点： (1）当雌蜂找到合适的产卵位点时，身体呈倒立状，后足扶持产卵鞘到选定的产卵位点；2）从开始插入产卵针到产卵鞘向后弹出，腹部第8～9节背板延伸部分与产卵鞘之间有两次大幅度的靠拢与分开，第一次靠拢与分开是保证产卵针以最佳的垂直角度插入果内，第二次是使产卵鞘向后弹出，将暴露在外的产卵针顺利地插入果内；3）雌蜂产卵针沿榕果直径方向（最短距离）插入果壁；4）前足与后足比中足发达，与整个产卵过程中支撑身体的行为有关 。

Oviposition behaviour of Philotrypesis pilosa Mayr (Hymenoptera:Agaonidae)

The species-specific mutualism between figs and pollinating fig wasps is one of the hot topics in coevolution studies. Figs host a large number of non-pollinating fig wasps besides pollinators. Philotrypesis pilosa Mayr is characterized by the extreme extension of the last two tergites of abdomen, in the form of ovipositor sheath, followed by the true ovipositor sheath. It is a cleptoparasite of Ceratosolen solmsi, the legal pollinator of Ficus hispida L. The oviposition process of P. pilosa was recorded with a digital camera. We found the following behaviors which were ignored by the previous authors: 1) When the female finds out a suitable site for ovipositing, it makes a headstand posture, freeing the hind legs to help the long ovipositor sheath to locate the site. 2) From the start of penetrating the syconium to springing the ovipositor sheath backwards, the extension part of abdomen tergites and the ovipositor sheath undergo two bouts of close-and-apart. The first bout of close-and-apart is beneficial to keep the stylets vertical so as to penetrate the wall easily. The second one is helpful to spring the ovipositor sheath backwards and make the exposed basal part of the stylets to squeeze into the wall without the clag of the sheath. 3) The stylets penetrate into the syconium along syconial diameter as the shortest way. 4) The fore and hind legs are more robust than the mid ones, which is related to their function of supporting the body during the oviposition.