A new study by Oregon State University states that biological control of the brown marmorated stink bug - an invasive pest that devastates gardens and crops - would be more effective in natural areas bordering crops or at times when certain insecticides aren’t being applied.

The study, published in the Journal of Economic Entomology, advances the understanding of using the samurai wasp for biological control of the brown marmorated stink bug, and has significant implications for Oregon’s growers of orchard fruits and nuts, said David Lowenstein, a postdoctoral research associate in Oregon State’s College of Agricultural Sciences and lead author on the study.

Biological control is the use of beneficial insects to manage other insects, which means using less pesticides. The brown marmorated stink bug, which is native to east Asia, has a taste for more than 100 types of crops, including blueberries, wine grapes, cherries and hazelnuts. During the 1990s, it invaded the United States and is now found in 44 states, causing millions of dollars in crop damage.

The stink bug was first detected in Oregon in 2004. Since then, OSU researchers have found the pest in 24 of Oregon’s 36 counties, and in all of the state’s major fruit-producing regions. The bug also causes nuisance issues when aggregating on the side of homes and sheds in the fall.

The samurai wasp, which is smaller than a pinhead, is native to the same region in east Asia as the brown marmorated stink bug. It lays its eggs inside stink bug eggs, preventing the stink bugs from hatching. Although it is unknown how it arrived in the U.S., surveys conducted in 2014-15 detected the wasp in several locations, like Oregon’s Willamette Valley.

Lowenstein said the research was necessary for growers, especially those in Oregon’s hazelnut industry, who use insecticides but who also want to use the samurai wasp to control stink bugs: “Since the discovery of the samurai wasp in Oregon, our research group at OSU has proposed biocontrol for managing the brown marmorated stink bug. We needed to validate the compatibility of this wasp in a commercial environment wher insecticides are being used.”