Brown marmorated stink bug may be widespread in Ontario - Watch for it!

During surveys conducted in 2012/2013*, the invasive brown marmorated stink bug (BMSB) was confirmed as established in the City of Hamilton and in Newboro (Leeds and Grenville County), ON. By "established", we mean both adults and immature life stages have been identified at these locations, indicating there is a reproducing population. In both cases, finds of adults (Figure 1) and nymphs (Figure 2) came following at least two years of confirmed homeowner reports in the area. In addition, we have also trapped BMSB adults at farms near Cedar Springs and Waterdown. Although BMSB was not identified in the crops at either location, there were multiple adults captured over several weeks, indicating the pest is probably established nearby (likely at low population densities). In the case of Cedar Springs, an adult was found at a homeowner site (indoors) earlier in the year, and of course, Waterdown is very close to known areas of infestation in Hamilton.

Figure 1 - BMSB Adult

Figure 1 - BMSB adult

Figure 2 - BMSB 5th instar nymph

Figure 2 - BMSB 5th instar nymph

What this means is that homeowner finds, especially multiple finds and at multiple locations in an area, need to taken seriously. BMSB adults move indoors in the fall to overwinter. While most may go unnoticed in unfinished spaces such as attics, some make their way into living spaces where they are easily detected.

To date, there have been confirmed homeowner finds in:

  • Hamilton (2010)
  • Burlington (2012)
  • Cedar Springs (2013)
  • Milton, Newboro (2012)
  • Toronto (2012)
  • Vaughan (2013)
  • Windsor (2013)
  • Niagara-on-the Lake (September 2013)
  • London (October 2013)
  • Kincardine (November 2013)
  • Paris (January 2014)
  • Fort Erie (February 2014)
  • Stoney Creek (February 2014)
  • and most recently Ottawa (March 2014).

In order to confirm homeowner finds of BMSB in a new area, we require an actual specimen. For example, we received photos of BMSB from Niagara Falls (winter 2014) and in St. Catharines (April 2014) but without an actual specimen, this cannot be added to our list. After we've received a few specimens, quality photos can be used to help track local abundance. Following recent media interest in BMSB in mid-April, we've had several new homeowner finds in Windsor and London, suggesting this pest is also established in those areas. Early detection is critical in mitigating economic injury to crops, and obviously we will follow up with surveys near these finds in 2014.

BMSB adults will start moving out of their overwintering sites soon; in 2013, the first adults were spotted mid-June. Nymphs will appear several weeks later.

The most important advice is to monitor for BMSB in crops and on preferred wild hosts (examples "tree of heaven", buckthorn) in adjacent landscapes / woodlots, keeping in mind this insect is highly mobile and can move into apples from adjacent crops or woodlots at any time in the season. There are no good thresholds in tree fruit. The presence of adults in the orchard is a good indication that nymphs are also present, and when nymphs are present, insecticide sprays are almost always necessary. In fact, a single BMSB found in 100 feet of tree fruit row along a wooded edge triggers intervention (see Early in the season, before BMSB builds up, directed border sprays may suffice (when BMSB is found only in the perimeter of the orchard or in adjacent plants). Products do not have much residual activity, and for this reason, alternate row middle (ARM, single side of tree) sprays have been recommended in the US. Later in the season (late July onwards), whole orchard applications are warranted. There are several products registered for control or suppression of BMSB in Canada; this information is posted on our website.

If you think you have found BMSB, please let us know so we can add new areas to the distribution map and to provide assistance. Call the Agriculture Information Contact Centre at 1-877-424-1300 or send an email to For more information and updates specific to Ontario, visit Details on the biology and management of BMSB, including an excellent video series, can be found at

* Funding for the project "Assessment of the Distribution and Natural Enemies of the Brown Marmorated Stink Bug in Southern ON" through the OMAF / MRA University of Guelph Partnership Agreement - Emergency Management Theme (2013-14), and financial support from the Grain Farmers of Ontario, the Ontario Apple Growers, the Ontario Tender Fruit Producers, the Niagara Peninsula Fruit & Vegetable Growers' Association, and the Grape Growers of Ontario.

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