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ARS Home » Southeast Area » Tifton, Georgia » Crop Protection and Management Research » Research » Publications at this Location » Publication #221284
Title: Effect of irradiation on the incidence of mating in Cactoblastis cactorum

Author
item Marti, Orville
item Carpenter, James

Submitted to: Florida Entomologist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/1/2008
Publication Date: 3/30/2009
Citation: Marti, O.G., Carpenter, J.E. 2009. Effect of irradiation on the incidence of mating in Cactoblastis cactorum. Florida Entomologist. 92:159-160.

Interpretive Summary: Cactus moths are a non-native pest species that threatens native cacti in the southwestern United States and in Mexico. In a control program to prevent its spread westward to the southwestern US and to Mexico, adult moths are irradiated and released to mate with wild moths. The radiation dosage used sterilizes the females and renders the males partially sterile so that their progeny are few in number, mostly male, and sterile. We needed to know whether irradiation of the moths affected mating frequency, and thereby their competitiveness. Two experiments were conducted to determine this. In the first experiment, individual normal females were caged with 5 normal or irradiated males. In the second experiment, individual normal or irradiated males were caged with 3-4 normal females and the females were removed daily and replaced with fresh moths until death of the male. Mating frequency was determined by dissections of the females. We found no consistent or significant differences in the frequency of mating between normal and irradiated male moths in either experiment. Female cactus moths mated 0-3 times, with most of them mating only once. Male cactus moths mated 0-5 times, with 1.5 matings being average for the males. We conclude that mating frequency in this species was not adversely affected by the radiation dosage used by the current control program.

Technical Abstract: No deleterious effects due to irradiation of male C. cactorum at 200 Gy were found, and no differences in mating frequency or longevity of irradiated male moths or of female moths mated to irradiated males were detected in our laboratory tests. Although many factors may influence the overall competitiveness of sterile insects released in a SIT program, we conclude that the irradiation (200Gy) of C. cactorum males used in the current SIT program does not adversely affect mating ability or frequency.