Progress 07/01/06 to 09/30/08

Outputs
Progress Report Objectives (from AD-416) Development of an efficient massrearing operation is critical to the successful mitigation of the invasive cactus moth, Cactoblastis cactorum. Initial trials in South Africa and in our USDA-ARS laboratory in Tifton, GA, demonstrated that C. cactorum could be reared on an artificial diet. However, low weight, low survival, and long developmental times indicated that improvements in the diet formula and presentation were needed. Subsequently, studies conducted in our laboratory demonstrated that wax- coated diet blocks and improved diet formulations could increase pupal weight and % survival, and could decrease the developmental time. Nevertheless, several challenges remain before efficient massrearing protocols can be established. For example, low fecundity results in a lower intrinsic rate of increase per generation and thereby increases the size of the brood colony required to produce the moths needed in the sterile insect technique releases. Observations have revealed that cactus moths that have developed in the laboratory on artificial diet are smaller, less fecund and have poorly developed fat bodies when compared with wild moths that developed in the field on live Opuntia. Therefore, to improve production in the massrearing of the cactus moth, we conclude that the artificial diet is lacking in appropriate feeding stimulants, sources of fat, and/or essential vitamins. Approach (from AD-416) Conduct a series of experiments to investigate the relationship between increasing concentrations of selected diet additives on developmental and reproductive parameters of the cactus moth. Diet additives will include sources of fatty acids, plant sugars, freeze-dried Opuntia cladode powder, vitamins and salts. Developmental and reproductive parameters will include developmental time, pupal weight, fat deposition, fecundity and fertility, mating propensity, and longevity. Experiments will be replicated 4-6 times. Regression analysis will be used for each ingredient to identify significant relationships and the optimum concentration. Additional experiments will be designed to examine the combination of ingredients that demonstrate significant positive effects. Significant Activities that Support Special Target Populations This project is related to the objective of the inhouse project: To investigate several different approaches toward pest management with a focus on integrating genetic strategies such as sterile insect techniques (SIT), biological control, and other biorational pest management tactics leading to the development of local and regional pest management systems for important invasive insects and insect pests of crops grown primarily in the Southeast, and the enhancement of the use of natural enemies for insect and weed biological control. No further research was conducted. The final annual report was in Fiscal Year 2008; the project was terminated 09/30/2008.

Impacts
(N/A)

Publications

Progress 10/01/06 to 09/30/07

Outputs
Progress Report Objectives (from AD-416) Development of an efficient massrearing operation is critical to the successful mitigation of the invasive cactus moth, Cactoblastis cactorum. Initial trials in South Africa and in our USDA-ARS laboratory in Tifton, GA, demonstrated that C. cactorum could be reared on an artificial diet. However, low weight, low survival, and long developmental times indicated that improvements in the diet formula and presentation were needed. Subsequently, studies conducted in our laboratory demonstrated that wax- coated diet blocks and improved diet formulations could increase pupal weight and % survival, and could decrease the developmental time. Nevertheless, several challenges remain before efficient massrearing protocols can be established. For example, low fecundity results in a lower intrinsic rate of increase per generation and thereby increases the size of the brood colony required to produce the moths needed in the sterile insect technique releases. Observations have revealed that cactus moths that have developed in the laboratory on artificial diet are smaller, less fecund and have poorly developed fat bodies when compared with wild moths that developed in the field on live Opuntia. Therefore, to improve production in the massrearing of the cactus moth, we conclude that the artificial diet is lacking in appropriate feeding stimulants, sources of fat, and/or essential vitamins. Approach (from AD-416) Conduct a series of experiments to investigate the relationship between increasing concentrations of selected diet additives on developmental and reproductive parameters of the cactus moth. Diet additives will include sources of fatty acids, plant sugars, freeze-dried Opuntia cladode powder, vitamins and salts. Developmental and reproductive parameters will include developmental time, pupal weight, fat deposition, fecundity and fertility, mating propensity, and longevity. Experiments will be replicated 4-6 times. Regression analysis will be used for each ingredient to identify significant relationships and the optimum concentration. Additional experiments will be designed to examine the combination of ingredients that demonstrate significant positive effects. Significant Activities that Support Special Target Populations This report serves to document research conducted under a reimbursable agreement between ARS and the International Atomic Energy Agency (IAEA). Additional details of research can be found in the report for the parent CRIS 6602-22000-035-00D, "Integrated Management Strategies Related To Insects For Established And Invasive Pest Species." Development of an efficient mass rearing operation is critical to achieving a successful Sterile Insect Technique (SIT) program against the invasive cactus moth, Cactoblastis cactorum. Initial trials in South Africa and in our USDA-ARS laboratory in Tifton, GA, USA, demonstrated that C. cactorum could be reared on an artificial diet. However, low weight, low survival, and long developmental times indicated that improvements in the diet formula and presentation were needed. Subsequently, studies conducted in our laboratory demonstrated that wax- coated diet blocks and improved diet formulations could increase pupal weight and % survival, and could decrease the developmental time. Nevertheless, several challenges remain before efficient mass rearing protocols can be established. For example, low fecundity resulted in a lower intrinsic rate of increase per generation and thereby increases the size of the brood colony required to produce the moths needed in the SIT releases. Also, observations revealed that cactus moths that developed in the laboratory on artificial diet were smaller and less fecund when compared with wild moths that developed in the field on live Opuntia. We initiated diet trials to investigate the influence that different organic acids and organic acid ratios might have on increasing the performance of the cactus moth on the artificial diet. We also measured cactus moth performance on diets with a lower pH, mineral and vitamin additives, reduced mold inhibitors, and cactus plant additives. The greatest improvements in pupal weights, developmental time, longevity, and survival were observed when cactus plant material was added to the diet. NP-304 - Crop Protection and Quarantine.

Impacts
(N/A)

Publications