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ARS Home » Southeast Area » Gainesville, Florida » Center for Medical, Agricultural and Veterinary Entomology » Insect Behavior and Biocontrol Research » Research » Publications at this Location » Publication #298817

Title: Performance improvement through quality evaluations of sterile cactus moths, Cactoblastis cactorum (Lepidoptera: Pyralidae), mass-reared at two insectaries

Author
item Hight, Stephen
item Carpenter, James

Submitted to: Florida Entomologist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/3/2015
Publication Date: 6/1/2016
Citation: Hight, S.D., Carpenter, J.E. 2016. Performance improvement through quality evaluations of sterile cactus moths, Cactoblastis cactorum (Lepidoptera: Pyralidae), mass-reared at two insectaries. Florida Entomologist. 99(sp1):206-214.
DOI: https://doi.org/10.1653/024.099.sp125

Interpretive Summary: An Argentine moth whose caterpillars feed on prickly pear cactus has become established in southeastern U.S. This moth threatens cactus biodiversity in natural settings and cactus used for agricultural and ornamental purposes. Management techniques were developed for this insect; some required the mass rearing and sterilization of cactus moths released into the environment to prevent successful reproduction of wild, fertile cactus moths. Expansion of the sterile insect release program required opening a new mass rearing, sterilization facility, but concerns were raised about reduced quality of moths from this new facility. Scientists with USDA, Agricultural Research Service, Center for Medical, Agricultural, and Veterinary Entomology, Gainesville, Florida, developed laboratory and field tests to evaluate the quality of sterile moths produced from the original and new facilities, and found that moths from the new facility were inferior in quality. After suggested changes were made in the rearing procedures, including moth collection, handling, sterilization, and packaging techniques, the tests were conducted again and the quality of sterile insects significantly improved. Higher quality sterile moths compete against wild cactus moths for mates, resulting in more sterile males mating with wild females. When a sterile male mates with a fertile female, her eggs fail to develop. Repeated release of sterile moths can reduce (even eliminate) the population of the wild cactus moth.

Technical Abstract: A bi-national program was established by Mexico and the United States to mitigate the threat of Cactoblastis cactorum (Berg) (Lepidoptera: Pyralidae), an invasive herbivore from South America, to native Opuntia spp. biodiversity and Opuntia-based industries. Mass-rearing, sterilization, and transport and release technologies assisted with the development of several control tactics including the sterile insect technique. Following the successful eradication of C. cactorum from Mexico and the elimination of C. cactorum from Alabama barrier islands, the bi-national program established an additional mass-rearing insectary for the production of sterile moths. Laboratory and field bioassays were conducted on sterile moths from both insectaries. Bioassays and assessments included moth mass, moth longevity, percentage of female moths mated at time of collection from the insectary, percentage of female moths mated 24 h after collection, flight ability, percentage recaptured after release in the field, and mean distance captured from release site. Data from the quality assessments and comparisons between the two insectaries were used as feedback mechanisms to make protocol changes in both rearing and handling that improved sterile moth quality and performance.