2007 Annual Report 1a.Objectives (from AD-416) The objectives of this cooperative research project is to provide a basic characterization of the flight/mobility traits of adult cactus moths and to compare the field dispersal of adult male and female moths to the predicted dispersal/mobility potential obtained from laboratory flight assessment studies. This research will support the Sterile Insect Technique (SIT) program being developed to control the spread of this invasive species in North America. 1b.Approach (from AD-416) Laboratory flight capacity and mobility will be quantified using computer-linked flight mills and actographs. Flight potential will be analyzed for moths that have undergone gamma radiation, the method of sterilizing insects released in the SIT program. Characterization of flight potential will also include unirradiated moths of both genders, adults emerging from the three different annual generations, and both mated and unmated moths. Mark-release-recapture field experiments will be conduced with mass-reared laboratory males using the trapping system previously developed by this laboratory. Since a female trap has not yet been developed, a grid of host trap plants will be arranged at various distances/directions from a female release point in pastured fields that do not contain native cactus plants. Trap plants will be assessed for eggstick deposition from the released mass-reared females. 3.Progress Report This report serves to document research conducted under a specific cooperative agreement between the USDA, Agricultural Research Service (ARS) and the Swiss Federal Institute of Technology (ETH), Zurich, Switzerland. Additional details of research can be found in the report for the parent CRIS project 6615-22000-022-00D, “Biological Techniques to Limit the Dispersal of Invasive Pests.” During the past year, the Authorized Departmental Officer’s Designated Representative (ADODR) monitored the activities of this project. The ADODR organized and hosted a 5-day training visit at field sites and cooperating ARS facilities for the ETH collaborating scientist. A site visit to ETH was conducted by the ADODR to evaluate progress, assist in research, and participate in manuscript preparation. Discussion of the project occurred at two international meetings that were attended by the ADODR and collaborating ETH and USDA scientists. The ADODR held three conference calls with collaborating scientists from ETH and USDA. In addition, multiple emails were sent between the ADODR and collaborating scientists to monitor their activities and insure progress on the project. A cooperative project with ETH was initiated to characterize flight/mobility traits of adult cactus moths, Cactoblastis cactorum. This moth is from Argentina and has become an invasive insect that poses a serious risk to the rich diversity of prickly pear cactus, Opuntia species, in North America. Knowledge of the flight behavior of the cactus moth is crucial for a better understanding of natural dispersal, and for both monitoring and control. We investigated daily flight activity and flight performance in relation to gender, age, mating status, and body size. Maximal flight activity for both mated and unmated moths occurred during twilight hours, while flight activity was low during daylight. Comparative assessment of the total distance flown, the longest single flight, and the number of initiated flights within a daily cycle did not detect significant effects of age or gender on flight performance among unmated and mated moths, except that the longest single flight decreased in length with increasing age in mated females. These findings suggest that pheromone trap captures of males likely indicate the simultaneous presence of females. Flight performance was highly variable, with a small portion of the population performing long unbroken flights, while the majority made short flights. There was no relationship between body size (weight) and flight performance within the same gender. However, higher pupal and adult body size and shorter life expectancy was found in females than in males. In conclusion, a few individuals, particularly young mated females, flying long distances may be important for active spread of a population and the colonization of new habitats.