L ovipositeur des tetranyques. The female genital region of Tetranychits itrticae C. L. Koch bas been described and compared with other species of Tetranychidae. A method bas been applied based on the fixation of females during oviposition. The extended genital region consists of an unpaired genital lip, an accordion-wise folded integument, a copula tory pore, and triangular lobes at the top of a tube constituted by the genital lip and the integument. During oviposition the tube is a continuation of the ventral surface. In connection with the passage of the egg an internal part of the tube is evaginated, of which the distal region presents some eight rings. The tube can be interpreted as a primitive ovipositor. The three apical lobes observed in other Actinotrichida are not present