Reproductive system and terminalia of the old world screw-worm fly, Chrysomya bezziana villeneuve (Diptera : Calliphoridae)

Abstract

The reproductive systems and terminalia of Chrysomya bezziana are described. The internal male reproductive system consists of paired testes, vasa deferentia, and accessory glands with a single seminal duct and sperm pump. The external male genitalia are composed basically of the aedeagus and hypandrium with their associated apodemes and a collar complex comprising a median epiphallus and paired pregonites and post-gonites. The internal female reproductive system consists of paired ovaries composed of polytrophic ovarioles, a common oviduct, 3 spermathecae, and a pair of tubular aceessory glands. After oviposition, follicular relics in the ovaries can be demonstrated which indicate previous gonadotrophic cycles. The external female genitalia are composed of sclerites from abdominal segments VI–VIII modified to form an ovipositor. The relationship of the terminalia during copulation is described.