Radiation Biology and Inherited Sterility in False Codling Moth (Lepidoptera: Tortricidae)

Abstract

False codling moth, Cryptophlebia leucotreta (Meyrick), male and female mature pupae and newly emerged adults were treated with increasing doses of gamma radiation and either inbred or out-crossed with fertile counterparts. For newly emerged adults, there was no significant relationship between dose of radiation and insect fecundity when untreated females were mated to treated males (N female by T male). However, fecundity of treated females mated to either untreated (T female by N male) or treated males (T female by T male) declined as the dose of radiation increased. A similar trend was observed when mature pupae were treated. The dose at which 100% sterility was achieved in treated females mated to untreated males (T female by N male) for both adults and pupae was 200 Gy. In contrast, newly emerged adult males treated with 350 Gy still had a residual fertility of 5.2% when mated to untreated females, and newly emerged adult males that were treated as pupae had a residual fertility of 3.3%. Inherited effects resulting from irradiation of parental (P1) males with selected doses of radiation were recorded for the F1 generation. Decreased F1 fecundity and fertility, increased F1 mortality during development, and a significant shift in the F1 sex ratio in favor of males was observed when increasing doses of radiation were applied to the P1 males.