Radiosensitivity and Regulation of Population Density in the Yellow Fever Mosquito (Aedes aegypti)

Populations of the yellow fever mosquito, Aedes aegypti (L.), were exposed to a series of selected levels of x-rays (0 R, 1600 R, 3200 R, and 6400 R). Females mated with irradiated males produced a normal complement of eggs regardless of the dose administered to the males; however, the viability of the eggs decreased with increasing dose to the males. Nontreated females mated with irradiated males (6400 R) produced eggs that were only 0.0005% viable. Females treated with 3200 R and mated with nontreated males failed to produce eggs. Sterile individuals of either sex or both sexes were introduced into nontreated populations having a sex ratio of 1:1. The introduction of sterile males was more effective as a population control method when the percentagewise variation in egg viability was considered; however, the number of individuals produced was 11% less when sterile females were introduced than was found with the comparable introduction of sterile males. The more practical means of population control of Aedes aegypti was concluded to be the introduction of sterile males. Contrary to observations in many species, the females were twice as sensitive to radiation as were the males when compared on the basis of the dose required to sterilize and with regard to the production of viable eggs.