Morphology of the reproductive tract of females of leaf beetle Chrysomela populi (Chrysomelidae: Coleoptera)

In this study, oocyte development and vitellogenesis of the leaf beetle Chrysomela populi are described and illustrated using light and scanning electron microscopies. The female reproductive tract of C. populi consists of a pair of ovaries, a pair of lateral oviducts, a common oviduct and a spermathecae. Each ovary has 14 telotrophic meroistic ovarioles. Each ovariole consists of a terminal filament, germarium, vitellarium and pedicel. Terminal filament is thin, long thread shaped. The germarium contains trophocytes towards the distal part, prefollicular cells and oocytes towards the proximal part in the young stage. The vitellarium contains 3–4 oocytes at different stages of development (previteloogenic, vitellogenic and choriogenic oocytes). Previtellogenic oocytes located towards the distal end of the vitellarium are surrounded by follicle epithelium. Vitellogenic oocytes are surrounded by a monolayer follicular epithelium, and their ooplasma is basophilic. The ooplasma of the oocytes in the choriogenic stage, which is the last stage of vitellogenesis, is filled with eosinophilic yolk granules of different sizes. Chorion is clearly differentiated between the vitelline membrane surrounding the ooplasma and the follicular epithelium. The pedicel connects the ovarioles with the lateral oviduct. A pair of lateral oviducts are connected to the common oviduct. A spermatheca is located towards the proximal part of the common oviduct. Spermatheca consists of a reservoir, duct and gland. The eggs are light yellow in color and the chorion is very thin. This study intends to contribute to female reproductive biology studies in Coleoptera and other insect order species, agricultural struggle studies in terms of researching C. populi .