Over the years, loss in natural habitat has seen the decline in numbers of around 50 species of butterflies in eastern Washington. But in a recent Washington State University study published in the Journal of Insect Conservation, researchers found that vineyards that create nearby natural habitats have three times the number of butterfly species and four times more butterflies than conventional vineyards.
WSU researchers recorded 29 separate species in “habitat- enhanced” vineyards, compared to nine species in conventional vineyards. In terms of raw numbers, they counted on average 20 butterflies in habitat-enhanced vineyards compared to five in conventional areas.
David James, an associate professor in WSU’s Department of Entomology, said butterfly increase was not the goal of the return of natural habitats. Instead, growers want to reduce pesticide usage. But as a side benefit, these vineyards are seeing the return of other inhabitants that had declined when natural habitat was removed.
To help control pests, they plant native sage-steppe shrubbery in and around their vineyards. These native plants, such as desert buckwheat shrubs, attract “good” insects like parasitic wasps, said James. Wasps feed on mealybugs and other “bad” insects that can be harmful to the vineyards.
“Conservation of butterflies is becoming an issue because all species are declining,” said James. “The habitat has been taken away by agriculture. This is a way of giving back. We’re showing that an agricultural industry can live alongside the natural ecology and help preserve and conserve it.”
This article appears in the July 2015 issue of Acres U.S.A.