2005 Peter Teal ( Improving Efficacy )

Improving Efficacy of Sterile Insect Technique for Mexican Fruit Fly and Mediterranean Fruit Fly

During 2004-2005 our research focused on several areas. The first was testing a new gel- based diet developed to take the place of the agar sugar block diet used to feed adult Tephritid flies prior to sterile insect technique (SIT) releases. Unfortunately, the gel formulation was deficient in protein which resulted in production of adults that were not efficient in producing pheromone or attracting females (Figures 1, 2). Formulation of the gel diet with additional protein, needed to improve reproductive competence, yielded an inconsistent formulation. Additionally, the gel diet was expensive and labor intensive to formulate. As such the gel diet was judged a poor substitute for the agar/sugar blocks.

Our second objective was to assess the efficacy of hormone therapy in field cage studies using the Mexican fruit flies. These studies are used as an indicator of field success for SIT studies. We found that untreated 6-day-old males had a much lower relative performance index and a significantly higher isolation index (Figures 3, 4). There was no difference in the relative performance index or isolation index between hormone treated 6-day-old males and mature males. Therefore, the hormone treatment was effective in making 6-day-old males mate as effectively as 12-day-old mature males in the field cage studies. We conclude from this that treatment with the hormone significantly improves the ability of sterile male Mexican flies to mate with wild females. Another area in which we conducted studies was to determine the effect