Submitted to: Florida Entomologist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: October 15, 2003
Publication Date: December 15, 2003
Citation: Hight, S.D., Bloem, S., Bloem, K.A., Carpenter, J.E. 2003. Cactoblastis cactorum (Lepidoptera: Pyralidae):Observations of courtship and mating behaviors at two locations on the Gulf Coast of Florida. Florida Entomologist. 86(4):400-408. Interpretive Summary: The invasive cactus moth continues to spread westward along the Florida Panhandle destroying native species of prickly pear cactus. Spread of the moth into the southwestern United States and Mexico, areas that are rich in cactus diversity, is of great concern to environmentalists and agriculturalists. Scientists with USDA, ARS, Center for Medical, Agricultural and Veterinary Entomology in Tallahassee, FL and Crop Protection and Management Research Unit in Tifton, GA are looking into ways of controlling this insect and limiting its westward spread. To develop these control tactics, information is needed on when and where male and female moths mate. The majority of mating behaviors are initiated and completed in the early twilight (before sunrise). Females are busy laying eggs the first few nights after mating and do not mate again. This very limited and short mating time will guide the development of a Sterile Insect Technique (SIT) that may stop the moth and perhaps push back its leading edge. By mass- rearing and sterilizing large numbers of male moths to be released in particular locations and at the appropriate time, matings between sterile and wild moths become likely and these result in fewer and less-fit offspring.
Technical Abstract: Cactoblastis cactorum (Berg) has become an invasive pest of Opuntia spp. along the coastal areas of southeastern United States from the panhandle of Florida to South Carolina. Spread of this insect into cactus dominated natural areas of the United States and Mexico and into agricultural opuntia fields of Mexico is raising concerns within international governments and conservation organizations. Interest is growing in using the Sterile Insect Technique (SIT) to manage C. cactorum populations. Information on courtship and mating behaviors of this insect is important in the development and application of SIT. We conducted mating table studies and determined that this moth exhibits simple rather than elaborate mating behaviors and that courtship and mating take place briefly during morning twilight. Typically, females initiate calling, males respond to females, and copulation are complete before sunrise. Successfully mated females attract males within a short period (mean of 5.2 min), while unsuccessful females continue calling for about 40 minutes. Mating pairs remain in copula for a mean of 31.8 min. Generally, mated females are busy ovipositing the first few nights after mating, not exhibiting additional mating behaviors. A release of marked males revealed that males stay near the release site and can be recovered and identified for subsequent population estimate studies. This study on courtship/mating behavior is helpful to the ongoing C. cactorum research to develop a successful SIT program, identify the female calling pheromone, improve monitoring traps, and develop a technique to estimate adult moth population abundance.