Bridget Hatfield, a research scientist with Kemin Crop Technologies, talks about a garlic oil-based treatment that can repel and disrupt mating for spotted wing drosophila, an invasive insect. (Kyle Odegard/Capital Press)

DALLESPORT, Wash. — Folklore suggests that garlic keeps vampires away. It also works against the invasive insect spotted wing drosophila, said Bridget Hatfield, a research scientist with Kemin Crop Technologies.

AlliCURB MAX, a garlic oil-based biopesticide, is being sprayed on cherry orchards, blueberry bushes and other fields as a repellent for SWD.

Hatfield said treatments are pushing the pest out of fields and disrupting mating. She spoke to about 50 growers and scientists during a cherry pre-harvest tour in late May with the smell of garlic slight but noticeable in the air.

The biopesticide was launched about two years ago and Kemin continues to work with researchers and growers in trials. The product is gaining momentum, Hatfield said.

Experts said farmers, including those who grow cherries and berries, can face high pressure from SWD in some years depending on weather and other factors. The tiny fly lays its eggs in ripe fruit and larvae hatch and grow inside.

The invasive pest was first discovered in the Northwest about 15 years ago.

While there’s better understanding and management tools for the insect from when it first arrived, SWD still can be very damaging to crops and their economic value.

Formulations with essential oils containing thyme or rosemary have been used against pests, but Hatfield said garlic oil has great repellent properties, which makes it an excellent tool against SWD.

“It will have efficacy on all types of insects,” she said, adding that mites also would be deterred.

Field sanitation and cleaning up dropped fruit so it doesn’t rot also is key for dealing with SWD.

AlliCURB MAX can be used up to and through harvest time.

“It’s all made with food safe ingredients,” Hatfield said.

Organic farms can apply the product, and it can be used as part of an integrated pest management program, helping reduce the risk of insects developing resistance to pesticides.

Hatfield said the garlic smell will persist for two to three days after applications, then dissipate, and crop flavors also won’t be altered — at least for human senses.

Insects, however, are highly sensitive and will still be impacted, she said.

Elizabeth Beers, a Washington State University entomologist, said that she hadn’t field tested Kemin’s garlic oil-based product, but said new tools and tactics were needed for SWD.

“It’s a great idea,” Beers said, adding that she’s been chasing an oviposition deterrent for a decade to stop the flies from laying eggs in fruit.

“If you can stop that pathway of saying this is a good host for me, that’s all it takes to enhance your pest control,” Beers said.

Julie Pond, executive director of the Northwest Berry Foundation, said she wasn’t familiar with AlliCURB MAX, but said it seemed like a novel idea worth exploring.

“We need a toolbox. We really need to think about managing spotted wing drosophila in an integrated pest management sort of way,” Pond said.

Efficacy trials will make the difference in growing farmer confidence, Pond said.