Copulation and Egg-Production in Rhodnius Prolixus: the Role of the Spermathecae

Abstract

1. Mated females of Rhodnius prolixus lay eggs at approximately twice the rate of unmated females. 2. Males which have had their seminal vesicles or opaque accessory glands removed produce spermatophores at mating, but no spermatozoa appear in the spermathecae of the females. The females involved in such matings do not exhibit an increase in egg-production. 3. When females lacking their spermathecae are mated to normal males, the increase in egg production which follows normal matings does not materialize. 4. Implanting spermathecae from mated females into virgin females increases the egg-production of the host. Implanting spermathecae from virgin females or seminal vesicles or transparent accessory glands from males has no effect on the egg-production of the donor. 5. It is tentatively concluded that a blood-borne factor from the spermathecae containing spermatozoa is the primary stimulus to increased egg production in a mated female.