Radiosterilization vs. Chemosterilization in House Flies and Mosquitoes

Abstract

Laboratory tests were conducted during 1961 and 1962 to compare the effectiveness of males of the house fly, Musca domestica L., and the common malaria mosquito. Anopheles quadrimaculatus Say, sterilized by apholate or tepa and by gamma radiation. For radiosterilization, house fly pupae were treated 31-54 hr prior to eclosion with 2850 r and mosquito pupae at least 24 hr old with 10000 or 12000 r from a cobalt-60 source supplying 736 ± 33 r/min. For chemosterilization, house fly male adults 1 day old were fed 1% apholate in the diet for 3 days and mosquito male adults for 3-4 days after emergence. Mosquito male adults 0-24 hr old were also exposed to contact residues containing 7 mg/ft² of tepa. The most important criterion of effectiveness was the reduction in number of viable egg batches from females confined with both treated and untreated males. Results from chemo-sterilization equaled or surpassed those from radiosterilization. With mosquitoes, highly competitive, yet per manently sterile, males were more attainable with chemo-than with radiosterilization. With house flies either method seemed adequate. but the slightly greater degree of recovery after irradiation than after chemosterilization must be considered.