Selective lure for Bactrocera dorsalis based on shared palpal and antennal responses across three economically important tephritid species

Abstract

The oriental fruit fly Bactrocera dorsalis is a highly destructive and invasive pest that threatens global horticulture, causing economic losses due to fruit damage and quarantine regulations. While attract-and-kill baits are widely used to suppress fly populations, these baits also impact many non-target species. To achieve ecological sustainability, our study aimed to develop a method that selectively targets female fruit flies. Using gas chromatography coupled to electro-antennal or palpal detection (GC-EAD/GC-EPD), we identified compounds that elicited responses in the maxillary palp and antenna of three different fruit flies including B. dorsalis, Ceratitis capitata, and Zeugodacus cucurbitae. As previous studies indicated the significance of compounds whose detection was shared among fruit fly species, we composed blends of such “shared compounds”. To test the hypothesis that compounds active on the palps and antennae are complementary and synergize attraction, we thus formulated three blends, a palpal, an antennal and a combined blend. Compounds were formulated in a wax emulsion for slow release and tested on B. dorsalis fruit flies in six choice and large room laboratory assays, as well as field trials. A blend of both antenna and maxillary palp-active compounds attracted more B. dorsalis than blends based on either antennae or palps alone, and exhibited a female-bias in captures. Furthermore, the blend was highly selective, capturing very few non-target organisms compared to torula yeast, a lure considered to be selective. Such lures are important in advancing targeted pest control strategies, ultimately contributing to more effective management of the devastating B. dorsalis population, and safeguarding global horticulture productivity.