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ARS Home » Southeast Area » Tifton, Georgia » Crop Protection and Management Research » Research » Publications at this Location » Publication #150007
Title: RADIATION BIOLOGY AND INHERITED STERILITY IN FALSE CODLING MOTH (LEPIDOPTERA: TORTRICIDAE)

Author
item BLOEM, STEPHANIE - IAEA/TALLAHASSEE,FL
item Carpenter, James
item HOFMEYR, J - CRI/CITRUSDAL,S.AFRICA

Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/25/2003
Publication Date: 12/1/2003
Citation: Bloem, S., Carpenter, J.E., Hofmeyr, J.H. 2003. Radiation biology and inherited sterility in false codling moth (Lepidoptera: Tortricidae). Journal of Economic Entomology. 96(6):1724-1731.

Interpretive Summary: The false codling moth (FCM) is the most serious pest of citrus in South Africa, and it also is a pest of corn, cotton and many other crops. Many U.S. Federal and State Agencies have expressed concern that this pest could soon be introduced into the U.S. as a direct result of increased international trade and tourism between the U.S. and many African countries. USDA-APHIS Port Interception Network records indicate that these concerns are well founded. In this study we report the effect of increasing doses of gamma radiation on the fecundity and fertility of FCM when insects were inbred or out-crossed to untreated (fertile) mates. We determined the minimum dose at which treated females were 100% sterile when mated to untreated (fertile) males, and the minimum dose at which irradiated males produce 100% sterile offspring. In countries where FCM does not occur (e.g., the United States), the technologies and methodologies developed for a sterile insect technique (SIT) program to control FCM in South Africa could be available for use in an eradication campaign should FCM become established as an exotic invasive pest. The results from this study provide a foundation of knowledge to advance the development of these SIT strategies.

Technical 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 then 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.