白蛾周氏啮小蜂的行为学

BEHAVIOR OF CHOUIOIA CUNEA YANG (HYMENOPTERA:EULOPHIDAE)

白蛾周氏啮小蜂群集内寄生于美国白蛾蛹中，其卵、幼虫、蛹及产卵前期均在寄主蛹内度过。成蜂在寄主蛹中羽化后，先进行交配（无重复交配现象），随后咬一“羽化”孔爬出，其余的成蜂个体均从该孔羽化而出。刚羽化的雌蜂当天即可产卵寄生。雌蜂能咬破寄主化蛹时作的薄茧而到达蛹体产卵。有的雌蜂爬附于寄主老熟幼虫体上待其化蛹后再产卵寄生。一头寄主蛹中可出１２４～３６５头小蜂，雌雄蜂性比为４４～９５∶１。雌蜂在２１℃时的寿命为１５天。成蜂向光性很强。卵为牡蛎形，半透明，刚产时长０．０５４～０．０６５ｍｍ，产后１小时左右迅速吸水膨大，体积几乎为初产时的３倍。幼虫蛆形，无头无足，以寄主体内的血淋巴及器官组织为食。寄主蛹内的物质被取食殆尽，只剩下空蛹壳时，幼虫老熟，随即化蛹在寄主蛹内。在自然界，以老熟幼虫在寄主蛹内越冬。

Chouioia cunea Yang is a gregarious endoparasitoid of Hyphantria cunea (Drury). It passes its egg, larval, pupal and pre egg laying adult stages in the host pupa. The emerging adults also copulate inside the host pupa which is an empty shell after feeding by the parasitoid. Then a female bites a hole to come out, and all the other wasps usually follow her way through the hole. The females lay eggs soon after emergence by pricking host pupa with the ovipositor. The parasitoid larvae feed on haemolymph and organs in the host pupa. When the larvae mature, the materials inside the host pupa are all consumed. An average 244.5 individual wasps are reared from one host pupa with a high ratio of femalse (♀∶=45￣96∶1). Life span of female is 15 d at 21℃. In nature, the parasitoids over winter as mature larvae inside host pupa.