橘小实蝇成虫复眼结构及感光机制

Structure and photoreception mechanism of the compound eye of Bactrocera dorsalis Hendel

【目的】研究橘小实蝇Bactrocera dorsalis成虫复眼外部形态、内部显微结构和光感受机制。【方法】利用扫描电镜观察橘小实蝇成虫复眼外部形态,组织切片研究成虫复眼内部显微结构及在不同光环境下小眼结构的变化。【结果】橘小实蝇成虫复眼位于头部两侧,正面观呈半球形,表面光滑平坦;小眼间隙有感觉毛,单个小眼由角膜、晶锥、网膜细胞及其特化的视杆、基膜等构成,晶锥、视杆周围和色素细胞内均含有大量的色素颗粒。不同单色光处理后,小眼内的附属色素细胞色素颗粒沿小眼纵轴移动。白光、绿光和黄光处理后,附属色素细胞色素颗粒沿小眼纵轴均匀分布;紫光、蓝光和红光处理后,附属色素细胞色素颗粒主要集中在视网膜细胞远端和角膜的近端。【结论】橘小实蝇雌、雄成虫复眼在外形和内部结构上无差异,均属于并置像眼,屏蔽色素颗粒的移动是其复眼适应外界光环境变化的重要机制,该研究结果为筛选橘小实蝇成虫敏感光波并对其进行灯光诱杀提供了理论依据。

【Objective】To study the external morphology,internal microstructure and photoreception mechanism of compound eye of the oriental fruit fly（ Bactrocera dorsalis）. 【Method】The external morphology of compound eye of B. dorsalis adult was observed using a scanning electron microscope. The microstructure of compound eye and the structural change of ommatidia under different monochromatic lights were observed using histological biopsy.【Result】The compound eyes were hemispheric,smooth,and located on the lateral upside of head. The gaps among ommatidia were covered with interommatidial hairs. Each ommatidium was comprised of a cornea,a crystalline cone,retinula cells,a rhabdom and a basement membrane. There were abundant pigment granules in the retinular pigment cells,and in the surroundings of the crystalline cone and rhabdom. The pigment granules in accessory pigment cells moved longitudinally under different monochromatic lights. They were distributed uniformly along the longitudinal axis in the ommatidium under white,green and yellow light,while mainly clustered in the distal of retinular cells and proximal of cornea under violet,blue and red light.【Conclusion】There are no differ-ence in external morphology and internal microstructure of compound eyes between male and female of B.dorsalis,and the compound eyes of both sexes are apposition eyes. Their compound eye adapts to environmental light changes by the mechanism of pigment granules moving longitudinally. This research can provide a theoretical basis for screening sensitive lights of B. dorsalis adult for light trapping.