Studies on the eradication of Anopheles pharoensis Theobald by the sterile-male technique using cobalt-60. VI. Sperm activity in males irradiated with the sterilizing dose.

Abstract

Matings between unirradiated female Anopheles pharoensis Theobald and either normal or irradiated males (12,000 R) were carried out in breeding cages to investigate the sperm activity in γ-irradiated males. Normal or irradiated males, after complete matings With females, were replaced by irradiated or normal males and egg production and hatchability were recorded daily for the first 10 days. Replacing normal males by irradiated males caused a decrease in egg hatchability compared with the controls, but insemination by normal males did not nullify insemination by irradiated males. Sterilization of males with 12,000 R γ-rays did not damage the sperm, as the sperm of irradiated males competed successfully with that from normal males, whether it was present in the spermatheca before or after copulation with normal males. Delaying the mating of males for 5 days after irradiation did not restore viability of the sperm.