Brown marmorated stinkbug: how to identify and limit the spread of this new pest
The brown marmorated stinkbug, an insect not previously seen on our continent, is native to East Asia. Since its first detection in Pennsylvania in 2001, the bug has spread to over 35 states, including several bordering British Columbia, Ontario, and Quebec.
It is a very serious pest that feeds on a long list of host plants, including fruit trees, vegetables, field crops, and ornamental plants (over 300 host plants!). In the Mid-Atlantic states, where it reached seemingly plaguelike proportions in 2010, the brown marmorated stinkbug caused an estimated loss of $37 million to the apple industry. Clearly, there is reason to be concerned that this scenario could be repeated in Canada if stinkbug invasions continue to expand. Last year, an established population was found in Hamilton, Ontario. This news, plus the fact that the brown marmorated stinkbug has been present in the Portland area for about 10 years and recently established in south Washington state has prompted a warning in British Columbia.
In addition to causing damage to high-value crops, brown marmorated stinkbugs are a major nuisance to homeowners and businesses. Adult bugs often seek shelter inside houses and structures in the fall, much like boxelder bugs, and emerge from overwintering sites in early spring. They do not harm humans, cause structural damage, or reproduce in homes. The bugs however can be quite distressing when they enter households in large masses and emit unpleasant odour (“stink”).
How to identify the brown marmorated stinkbug?
The brown marmorated stinkbug appears similar to several other species of shield bugs and is often confused with common “brown” stinkbug, spined soldier bug, squash bug, and western conifer seed bug.
Adult marmorated stinkbugs are 13 to 17 millimetres long and dark mottled brown. They have distinct white bands on the antennae, smooth “shoulders” (without any toothed edges), and red eyes. The exposed edges of the abdomen have black and white pattern, and the white triangles are distinct and broader compared with other similar appearing bug species. They tend to cluster together in groups.
Adult females lay eggs in clusters of 20 to 30. Eggs hatch and young bugs (nymphs) emerge. Early-stage nymphs feed in groups but disperse as they get older. Like bedbugs, both adults and nymphs of stinkbugs feed on their host, but in this case the host is a plant.
How you can help to limit its spread?
Brown marmorated stinkbugs are adept hitchhikers and can easily move with shipping containers, cargo, and vehicles across large distances. They are on the move and will likely arrive in British Columbia sooner or later to eat our crops, impact our wineries, and stink our homes.
Because there is no reliable survey method identified (as of yet), limiting the spread of this new pest will rely on public detections. Lots of eyes will help with the early detection of brown marmorated stinkbugs. Timely detection will facilitate response by the pest control experts and allow for the implementation of strategies to limit its spread in the area. If you find “suspect” stinkbugs, contact the B.C. Ministry of Agriculture offices in Abbotsford and Kelowna. (For more information, see the ministry’s alert.)