Brown marmorated stink bug breeding successfully in Ontario

As an update to our reports of homeowner finds of brown marmorated stink bug (BMSB), we have now found conclusive evidence that this invasive alien pest has established itself in Ontario. Several life stages of the brown marmorated stink bug (BMSB), including eggs, nymphs, and adults have been collected over the last few weeks in a homeowner garden and a wildlife sanctuary in Hamilton, ON. BMSB adults have previously been found at multiple homeowner sites (indoors) in Hamilton (2010-2012) and at a single site in Newboro. There have been unconfirmed reports of BMSB in other locations OMAFRA and the University of Guelph have ongoing surveys for BMSB in field crops across the province*; to date, the pest has not been detected in any crop.

BMSB is an invasive alien species native to China, South Korea, Taiwan and Japan. It was introduced to North America in the mid 1990s, and was first detected in Allentown, Pennsylvania in 2001. While BMSB is capable of natural spread, the pest is also an excellent hitchhiker and can be moved over large distances in cargo and vehicles. At present it has been found in at least 37 states, though many of these are simply detections rather than confirmed as established in the field.

BMSB has a very broad host range that includes tree fruit, berries, grapes, vegetables, agronomic crops, ornamental trees and ornamental shrubs. Damage results when nymphs and adults feed on either vegetative or fruiting plant parts. The pest is highly mobile and can readily switch hosts, moving between crops throughout the growing season. In 2010 and 2011, BMSB was seen in extremely high numbers in the mid-Atlantic region of the US, where growers reported significant economic loss in multiple crops (particularly tree fruit).

Adults overwinter in sheltered areas that may include homes and other heated buildings. As they can aggregate in very large numbers, the BMSB has become a considerable nuisance pest for home owners where established. While the bugs do not bite humans, they will release a foul smell when handled or otherwise disturbed. They do not lay eggs or reproduce inside structures. Aggregation in artificial structures is not common among stink bugs, and is a behaviour that provides an early warning of where BMSB has become established. At the very least, these interceptions provide important information on where to target future surveys.

At this point in the year, the most common life stages you are likely to observe are nymphs and adults. BMSB is a fairly large stink bug with several key distinguishing features:

Adults (Figure 1):

  • 14-17 mm in length
  • two obvious white bands on otherwise dark antennae
  • inward-pointing white triangles between dark markings along the edge of the abdomen
  • smooth edge along the pronotum or "shoulders"
  • mottled brown-grey dorsally and a pale underside
  • membranous portion of forewings have a reddish tinge
  • brown legs with faint white banding

Figure 1. Brown marmorated stink bug adult

Figure 1. Brown marmorated stink bug adult (Photo credit: Jennifer Read, NRCan).

Late instar nymphs (Figure 2):

  • pattern on edge of abdomen beginning to develop
  • white bands on antennae
  • obvious white bands on legs
  • pronotum has toothed edge

Figure 2. Brown marmorated stink bug nymph

Figure 2. Brown marmorated stink bug nymph. (Photo credit: David R. Lance, USDA APHIS PPQ,

How can you help?

Early detection is important to the long term success of management programs. We need to have a better understanding of where this pest is and how well it is established. There is a monitoring network for this pest; however, we have a better chance of finding pockets of small populations if more people are looking. Tracking the distribution and spread is essential. If you think you have found BMSB, contact the Agriculture Information Contact Centre at 1-877-424-1300 or email Place the insect in a leak proof container and add rubbing alcohol, or freeze to kill it.

For more information visit the OMAFRA website

* Project funding provided by the Grain Farmers of Ontario.


For more information:
Toll Free: 1-877-424-1300