The mating ability of males of Culex pipiens fatigans Wiedemann sterilized with apholate or tepa.

The chemosterilants apholate and tepa are known to induce a high degree of sterility in the males of Culex pipiens fatigans. The studies reported show that 36-hour-old apholate-and tepa-sterilized laboratory-bred males can inseminate the same number of laboratory-bred or wild females as can normal laboratory or wild males in the first 48 hours of their lives. Males sterilized by either compound were found to be more competitive in mating with normal laboratory females than were the normal laboratory males. When normal virgin females were mated first with sterile and then with normal males or vice versa, the sperms of the first mating always decided the fate of eggs. Apholate-sterilized laboratory males were not only compatible with wild females but could even induce the same level of sterility in them and were fully as competetive in mating as normal wild males. The authors stress that it has still to be ascertained whether these encouraging laboratory findings would apply in field conditions.