(HW) - US researchers have developed a new lure for the fruit pest spotted-wing Drosophila (SWD) using compounds in wine and vinegar which are most appealing to the flies.

Both wine and vinegar have already been used in lures for SWD, which is an established pest in the North American fruit industry and is also establishing in the UK.

But US Department of Agriculture (USDA) entomologist Peter Landolt and research associate Dong Cha, with Oregon Department of Agriculture colleagues, took what they called "a top-down approach", isolating individual compounds from both and evaluating them in laboratory and field trials.

These showed that SWD prefers some types of wine and vinegar over others, with Merlot wine and rice vinegar attracting more male and female flies than Chardonnay wine and apple cider vinegar, for example.

Of the chemicals evaluated, acetoin and methionol triggered the strongest responses in SWD when combined with acetic acid and ethanol. "If one of those is missing, you get significantly lower attraction," Cha said.

Oklahoma-based Trécé now markets the compounds together with a lure, as Pherocon SWD.

Landolt added: "The lure's availability should provide better information to growers who use trap-catch data to make pest-management decisions."