Spotted wing drosophila do not depend on fruit and berry growers’ crops for their food, shelter, and reproduction. They can live in non-crop host plants nearby from which they can move into orchards as commercial fruits begin to ripen.
A new guide to non-crop host plants used by spotted wing drosophila (SWD) has been published by Oregon State University, compiling information from collections made in Michigan, New York, Florida, California, Oregon, Washington and British Columbia.
A three-page fact sheet titled “Noncrop Host Plants of Spotted Wing Drosophila in North America” is available as a free PDF on the Michigan State University spotted wing drosophila website (www.ipm.msu.edu) and at other university websites. It lists about 40 kinds of non-crop fruits that support SWD larvae, along with color pictures of some of them.
“This information combines what was learned from collections of fruit in wild and agricultural habitats since this pest arrived in North America seven years ago,” said Dr. Rufus Isaacs, Michigan State University entomologist who, along with his colleague Steve Van Timmeren, collected fruit and then held it to see what insects emerged.
The research entomologist authors, in addition to Isaacs, include Jana Lee, USDA-ARS Horticultural Crops Research Unit; Amy Dreves, Oregon State University; Greg Loeb, Cornell University; Howard Thistlewood, Pacific Agri-Food Research Centre, Agriculture and Agri-Food Canada; and Linda Brewer, Oregon State University.
“The information can be used by growers and others to consider which areas may be most likely to provide a reservoir of habitat for this pest,” Isaacs said. “There is little information on the effectiveness of removing these non-crop host plants from a landscape, but high densities of these suitable hosts can be expected to increase pressure from SWD.”
Not surprisingly, the list includes relatives of domesticated crops—cherries, berries—but it also includes weeds like pokeweed and nightshade and shrubs like honeysuckle.