Comparison Of The Female Reproductive System Between Panorpidae And Bittacidae (Mecoptera)

The organs of female reproductive system are important for insect reproduction and play a crucial role in producing gametes,mating and oviposition.Therefore,the morphological structures of female reproductive system may provide basis and reference for classification and phylogenetic analyses of insects.However,the research of the ultrastructure of female reproductive system is still scarce.Bittacidae and Panorpidae are the two largest families in Mecoptera.Previous studies mainly focused on the external morphology of female reproductive system.The research of the ultrastructure of female reproductive system is only involved in two species of Panorpidae,but remains largely unknown in Bittacidae to date.In this thesis,the female reproductive system of Bittacidae and Panorpidae were compared using light microscopy.We also investigated the ultrastructure of the accessory glands of Dicerapanorpa magna(Chou,1981),and the spermatheca of Sinopanorpa tincta(Navás,1931),D.magna(Chou,1981),and Bittacus trapezoideus Huang & Hua,2005 by scanning,and transmission electron microscopy.The female reproductive system is composed of paired ovaries,lateral oviducts,a common oviduct,a pair of accessory glands,and a spermatheca.A pair of lateral accessory glands is found in the female reproductive system of the Bittacidae,but is absent in Panorpidae.The ovary is asymmetrical in Panorpidae and the number of ovarioles is unstable in Cerapanorpa and Sinopanorpa,but symmetrical and constant in Bittacidae.The accessory glands in Panorpidae is longer than that of Bittacidae.The spermatheca is bean-shaped and attached with muscle fibers in Panorpidae,but is spherical or pear-shaped in Bittacidae.The spermathecal duct is divided into thicker,normal,and slender parts in Panorpidae,but is extremely-elongated and coiled in Bittacidae.The spermatheca of Panorpidae and Bittacidae comprises a basal lamina,an epithelium,a cuticle,and a central lumen from the outside to the inside.In Panorpidae the distal portion of the spermathecal reservoir consists of a single-layered epithelium and lacks secretory activity.The epithelium of the proximal portion of the spermathecal reservoir and duct comprises secretory cells,indicating active secretory activity.The epithelium of the spermatheca and its duct of Bittacidae has glandular cells,both of which have secretory function.