Location: Tropical Crop and Commodity Protection Research
Project Number: 2040-22430-027-032-I
Project Type: Interagency Reimbursable Agreement
Start Date: Sep 1, 2019
End Date: Aug 31, 2022
1) Testing of non-nutritive sugar formulations as a new control method for regulatory use in fruit fly action programs. 2) Test reduced numbers of SPLAT ME attract-and-kill spots per square mile in CA and the field quality of sterile Bactrocera dorsalis. 3) Validation and technology transfer of pathway and strain ID tools for Anastrepha ludens.
Erythritol (ingredient of natural sweetener Truvia) has been shown to have insecticidal properties on Drosophila flies upon consumption. Bioassays will be conducted on multiple species of Bactrocera, to include B. dorsalis. In addition to survival, oviposition will also be measured for treated and control flies. Work will focus on enhancing the palatability of erythritol erythritol using phagostimulants. Confirmatory trials will be conducted using papaya fruit in laboratory and also in field using field cages. Under MAT, a targeted density of 600 stations per square mile is commonly used against B. dorsalis when it is found in the U.S. Mainland. For this project Mark-Release-Recapture (“MRR”) experiments with sterile B. dorsalis will be conducted in California to measure the effectiveness of the current and reduced application densities. The number of flies killed per station will be assessed by having a subset of stations consist of traps. In addition to information on MAT, this experiment will provide valuable data on the field quality of sterile B. dorsalis. Leveraging existing population genetic analyses and reduced SNP genotyping assay (Dupuis et al 2019), the ability to accurately identify source and strain of Mexfly will be investigated. To increase the confidence in the assay and validate its accuracy, large panels of known wild and known release line flies will be genotyped across this developed panel. From this, specific methodologies will be developed to allow for exclusion of the rearing lines as the source of possible interceptions, as well as placing probabilities on the geographic source of interceptions deemed to be of wild source. Additional markers can be intergrated into this assay as needed, including potentially loci linked to the black pupae trait via QTL analysis, or additional SNP markers identified in further analysis to continue to improve this diagnostic tool.