阿拉善双峰驼阴道蝇蛆的形态结构观察

摘要

The vaginal myiasis of Alxa Bactrian camels is caused by the larvae of Wohlfahrtiamagnifica parasitized in the vagina.In this study, the morphological structure of the larvae of vaginal myiasis agent in Alxa Bactrian camels was observed.The first instar larvae are obtained from the female Wohlfahrtia magnifica captured in the field or around the vulva of Alxa Bactrian camels which were just oviposited by the female Wohlfahrtia magnifica.The second and the third instar larvae were taken from the vagina lesions in diseased Alxa Bactrian camels.We used the scanning electron microscope, integrated anatomical microscope, and ultra depth imager etc.to observe its structure and to give a description.Through anatomical microscope, we can observe that the larva has 12 segments, which are a bilobed pseudocephalon segment, three thoracic segments, seven abdominal segments and an anal segment, respectively.Under electron microscope, we can see many sensilla and a pair of mouthhooks at bilobed pseudocephalon of the first instar larva, and the mouthhooks attach to the cephaloskeleton.The surface of larva has a lot of hard spines, and the number and arrangement of spines are different on each segment.The anterior respiratory spiracles of the second and the tertiary instar larvae present a fan-like structure carrying five branches.The anus is in the last segment and hemispherical in shape.The posterior spiracles hide in the spiracular cavity.%阿拉善双峰驼阴道蝇蛆病是由黑须污蝇 (Wohlfahrtia magnifica) 幼虫寄生而引起的一种疾病, 论文对阿拉善双峰驼阴道蝇蛆形态结构进行了观察.一期幼虫为从野外捕捉的黑须污雌蝇体内获得或从双峰驼阴门附近采集雌蝇刚排出的一期幼虫;在患病驼阴道病灶处可以捕捉到二期、三期幼虫, 采用扫描电子显微镜、一体式解剖显微镜、超景深成像仪等进行观察并描述.在解剖镜下看到蝇蛆具有12段体节, 分别为1段双叶伪头、3段胸节、7段腹节和肛部.扫描电子显微镜下观察到一期幼虫双叶伪头上具有很多感受器和一对口钩, 口钩附在头骨架上, 蝇蛆体表有很多硬刺, 每一体节上刺的数量与排列方式不同.黑须污蝇二期、三期幼虫前呼吸孔呈扇形, 由5个分支组成.肛部为最后一体节, 呈半球型, 后呼吸孔隐藏在气门腔内.