D3455: Efficacy of natural products as oviposition deterrents for invasive fruit flies

Oviposition deterrent activity of a natural product-based putative oviposition deterrent mixture (OviX; Patent pending) was evaluated against Bactrocera dorsalis (oriental fruit fly, OFF) and bioactive key-deterrent compounds were identified. Two-choice assays using guava-juice infused agar (for OFF) treated with OviX deterred OFF oviposition in a dose-dependent manner with 87% reduction at 20mg dose compared to a solvent control (hexane). When individual components of OviX were tested, four compounds significantly reduced OFF oviposition (negative compounds), two compounds had no effect (neutral compounds), and other compounds stimulated (positive compounds) oviposition. Two-choice tests with the blend of four OFF “negative” compounds failed to elicit the same level of oviposition reduction as OviX, whereas the addition of two “neutral compounds” recovered oviposition deterrence in parallel with OviX. Subsequent subtraction tests showed that only one of the two neutral compounds was necessary and the resulting 5-component blend with a neutral compound plus the four negative compounds showed the same level of OFF oviposition deterrence as OviX. These results indicate that developing synthetic chemical oviposition deterrents from natural products could be effective against oriental fruit fly, providing their biodegradability and safety to the environment.