The Migration of Spermatozoa in the Female of Rhodnius Prolixus Stal

In Rhodnius, as in many insects, a spermatophore containing the semen is deposited in the bursa copulatrix of the female during copulation, and the spermatozoa then migrate to the spermathecae where they are stored until they are used in fertilization. In some insects this migration may be very complex, as in the Lepidoptera (Musgreave, 1937; and many others), and in seeking to explain these movements many authors have assumed that the spermatozoa play an active part and some have invoked chemotaxis (Heberdey, 1931). Evidence to be presented in this paper will demonstrate that the migration in Rhodnius is a result of contractions in the female ducts set up by a secretion from the male acting through a peripheral nervous system and that the spermatozoa play no active part in the migration. The spermatophore of Rhodnius has been described by Khalifa (1950a), and its mode of formation and the events at copulation will be examined in a later paper. All that concerns us here is that the spermatophore is placed in the bursa copulatrix so that it fills the bursa and the slit containing the semen encloses the lip-like vestibulum (see Fig. 1). By killing the females at various times after copulation, and sectioning the reproductive ducts, it was ascertained that the spermatozoa travelled to the spermathecae via the lumen of the common oviduct and that they began to arrive at the spermathecae within 5-10 min after the termination of mating. There was no particular orientation of the spermatozoa in the oviduct or spermathecae.