Inherited sterility in Cactoblastis cactorum (Lepidoptera: Pyralidae)

Newly emerged male and female adult cactus moths, Cactoblastis cactorum (Berg), were treated with increasing doses of gamma radiation, and the moths were outcrossed to fertile counterparts. Fecundity of the moth pairs was not affected by increasing doses of radiation. The minimum dose at which treated females were found to be 100% sterile when mated to untreated males was 200 Gy. Fertility of treated males declined with increasing doses of radiation to approach 0%, near 500 Gy. Inherited effects resulting from irradiation of P males and females were expressed in the F-1 generation as increased developmental time from oviposition to larval eclosion, increased egg mortality, and increased neonate to adult stage mortality. A shift in the F-1 sex ratio in favor of males was not observed.