Observations on the Genital System and Alimentary Canal of a Lamiid Beetle, Nupserha bicolor

The genital system and alimentary canal of both sexes of adult Nupserha bicolor s.sp. postbrunnea have been examined. In the female, the posterior end of the rectum is enclosed within a membranous jacket. The membranous jacket represents the tenth segment and is much more prominent than in the male. The jacket enclosing the rectal end runs a short course parallel with the vaginal passage through a common chitinous capsule representing the ninth segment, in which the openings of the anus and the genital passage lie. The chitinous capsule thus looks like a ‘cloacal chamber’. It disappears when the ovipositor is shot out. In the male, the posterior end of the rectum runs straight to the anus. The anus is located within the membranous remnant of the tenth segment. In the genitalia of the female, one remarkable peculiarity is observed distally in the eighth tergite of the adult female. At this level, the eighth tergite and the dorsal portion of the intersegmental membrane between the eighth and ninth segments lie superimposed upon one another and unite medially. On one side a condyle and an oblique socket are formed. The condyle of each side projects into the socket of the other side to form a ball-and-socket apparatus. The mechanism disappears proximally in the eighth tergite. The structure is absent in the male.