Submitted to: Florida Entomologist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/12/2008
Publication Date: 5/20/2009
Citation: Hight, S.D., Carpenter, J.E. 2009. Flight phenology of male Cactoblastis cactorum (Lepidoptera: Pyralidae) at different latitudes in the southeastern United States. Florida Entomologist. 92(2):208-216.
Interpretive Summary: A moth from northern Argentina was found in North America for the first time in 1989. This moth causes damage only to prickly pear cactus. The insect’s spread from the Florida Keys along the Gulf Coast to Mississippi and the Atlantic Coast to South Carolina has raised concerns about this moth’s unavoidable and unwanted impact on native, agricultural, and ornamental cactus in its new homeland. The bright orange-red, black-spotted caterpillars feed inside the pads of all prickly pear cactus with flat pads. Scientists with USDA Center for Medical, Agricultural and Veterinary Entomology in Tallahassee, FL and Crop Protection and Management Research Unit in Tifton, GA are looking into ways to monitor and control this insect. The ARS cactus moth team has developed an adult moth trapping system that is baited with a synthetic female sex pheromone. Males fly into the traps looking to mate with a female moth, but are caught on the traps’ sticky bottom. We used these traps at several sites infested with the cactus moth to identify at what time of year the adults are flying and the number of generations the moth has each year. Trapping for male adult cactus moths was conducted at several sites over several years from Puerto Rico to South Carolina. At the sites that have at least some cool temperatures in the winter (South Carolina to central Florida), the moths have three distinct flight periods (generations) per year. Each flight period lasts about two months. At the tropical sites of Puerto Rico and the Florida Keys, the cactus moth does not have distinct generations. Temperatures at these sites stay warm enough for moths to complete their life cycle throughout the year. This information helps scientists working to monitor and control this invasive insect by identifying the time of year when to use traps to look for the presence of the moth, to create maps that predict when and what life stage of this moth to look for, and schedule the appropriate time to release sterile cactus moths that will mate with wild moths so that they do not have any viable offspring.
Technical Abstract: Long term trapping studies of the invasive moth Cactoblastis cactorum (Berg) were conducted at various latitudes from Puerto Rico to South Carolina. Three flight periods per year were identified at the five temperate sties studied, which covered the majority of the insects’ mainland United States infested range. In general, the three flight times across a latitudinal gradient from south Florida to central, coastal South Carolina were a spring flight during February-May, a summer flight during June-August, and a fall flight during September-November. At any one site, each flight period lasted about two months. In the tropical areas of the Florida Keys and a Caribbean Island, the insect had overlapping generations throughout the year. Previous studies conducted of this insect as a biological control agent indicated two flight periods per year in the insects’ native range of Argentina and introduced range of Australia and South Africa. A newly developed synthetic sex pheromone baited trap was a good indicator of generational time for this insect, and trapping in previously studied areas will likely identify three generations rather then two. Initiation and timing of the three generational flights has importance in the current United States and Mexico monitoring program for the presence and expansion of this invasive insect, development of mapping programs to identify appropriate monitoring times, and management efforts using the Sterile Insect Technique.