Project Number: 2040-43000-018-005-I
Project Type: Interagency Reimbursable Agreement
Start Date: Aug 1, 2019
End Date: Jul 31, 2022
The objective of this Interagency Agreement is to identify attractants for improved detection of female Oriental fruit flies (OFF), Bactrocera dorsalis. In recent years, incursion of OFF have increased in South Florida, threatening production of avocado, mango and many specialty crops. In August 2015,establishment of a breeding population in Miami-Dade County triggered a multimillion dollar quarantine and eradication program. Methyl eugenol is a powerful attractant for male OFF. Torula yeast/borax solution is used currently for detection of females, but it is a weak attractant with a short field life. New and more potent female attractants are needed for improved OFF detection, particularly near ports of entry to prevent establishment. Here we propose to bioassay and identify attractants for adult female OFF from volatile chemicals emitted from a variety of attractive food baits, microbial sources and plant materials. The most promising compounds from initial screening will then be used to develop prototype baits and lures for further evaluation.
Using laboratory-reared flies, conduct behavioral bioassays (two-choice tests in olfactometers, wind tunnels, and/or field cages). Determine relative attraction of different food baits (e.g. torula yeast, various strains or species of yeasts, protein hydrolysate, grape juice and wine, vinegar, host fruits, and their combinations) to female Oriental fruit flies (OFF). Identify field sites with established OFF populations. Conduct field trapping experiments to compare capture efficacy of the top 3-4 food baits identified from laboratory bioassays. Collect headspace volatiles released from the most attractive food baits (adsorbant volatile traps and solid-phase microextraction). Identify potential attractants by measuring insect olfactory response to compounds within the volatile collections (conduct coupled gas chromatography-electroantennographic detection [GC-EAD] to determine which compounds the insect can smell, followed by gas chromatography-mass spectrometry [GC-MS] to identify those compounds). If available, purchase authentic EAD-active synthetic compounds to confirm chemical identity and insect olfactory response. Prepare prototype lures using the most promising compounds (behaviorally determined by systematically testing potential attractants individually and in various blends). Conduct field trapping experiments to compare efficacy of prototype lures to the standard liquid protein bait. Using subtraction tests, determine key attractants from the prototype lure. Using dose-response tests, optimize the release rates of individual key attractants. Conduct field tests of the most promising attractants in Florida.