Avoid the Sting of Stink Bugs

The Brown Marmorated Stink Bug (BMSB) provincial survey 2013* has been underway since May. Overwintering adults were first detected at our hot spots in Hamilton beginning mid-June, and by early July, the first nymphs were found on buckthorn. Populations have been building ever since. We have been finding BMSB nymphs and adults (Figure 1) on a wide variety of common landscape trees and shrubs, as has been reported in the US. So far, we have only found breeding populations in localized areas in Hamilton.

Brown marmorated stink bug nymph and adult

Figure 1. Brown marmorated stink bug nymph (left) and adult (right).

BMSB numbers are at their peak by late August and early September. At this point in the season, most individuals will have completed their development and adults will be looking for any remaining food sources prior to overwintering. As a late-harvested crop, apples are at higher risk.

Early symptoms of injury, particularly in apples, can be difficult to detect (Figure 2). Sometimes white sugar crystal residues and / or a small hole can be seen in the centre of discoloured feeding sites. Older signs of stink bug damage appear as sunken spots, with corky brown tissue beneath the skin (Figure 3). Fruit that appears unblemished at harvest can come out of storage with brown spots and damage similar to that caused by bitter pit.

Injured apple due to stink bug

Figure 2. Early stink bug feeding injury may appear as discolored spots (left), with white sugar crystal residues and/or a small hole in the centre the feeding site (right). (Peter J. Jentsch, Cornell Univeristy Hudson Valley Lab)

Injured apple due to stink bug

Figure 3.Older signs of stink bug damage appear as sunken spots, with corky brown tissue beneath the skin (left). Injured fruit that appears unblemished at harvest can come out of storage with brown spots similar to that caused by bitter pit (right). (Peter J. Jentsch, Cornell Univeristy Hudson Valley Lab)

The following link has some excellent photos of stink bug damage in apple: http://hudsonvf.cce.cornell.edu/scouting%20reports/BMSB%20Project/BMSB%20Alert%209-26-12.pdf.

Here are some of the pre-harvest tips being recommended to growers in other production areas:

  • Scout orchard perimeters. Injury is often greatest along wooded edges, especially those where preferred hosts are abundant ("Tree of Heaven", Catalpa, buckthorn**, etc.). Consider in-season monitoring of these hosts on your farm next year, as an early warning that BMSB is established nearby.
  • Look up. BMSB tend to prefer the upper canopy, so use a ladder to increase your ability to detect this pest when numbers are low.
  • Monitor often. BMSB are strong flyers and can move from landscape hosts into crops very quickly.
  • There are no thresholds in tree fruit. BMSB can be difficult to detect, and it doesn't take many stink bugs to cause significant economic loss in apples.

Remember that there are other stink bugs capable of causing damage to apples. If you think you have found BMSB, please contact us immediately via the Agriculture Information Contact Centre 1-877-4524-1300 or email ag.info.omafra@ontario.ca. For more information on BMSB, visit www.ontario.ca/stinkbug and www.stopbmsb.org.
"*" Funding for the project "Assessment of the Distribution and Natural Enemies of the Brown Marmorated Stink Bug in Southern Ontario" was obtained through the OMAF and MRA / University of Guelph Partnership program Emergency Management Theme, with the financial support of the Grain Farmers of Ontario, the Grape Growers of Ontario, the Niagara Peninsula Fruit and Vegetable Growers' Association, Ontario Apple Growers, and the Tender Fruit Producers Marketing Board. The BMSB Research Team includes Dr. Cynthia Scott-Dupree (University of Guelph), Dr. Tara Gariepy (Agriculture and Agri-Food Canada), Hannah Fraser and Tracey Baute (Ontario Ministry of Agriculture and Food and Ministry of Rural Affairs), with the support of several other OMAF and MRA Agriculture Development Branch staff.

"**"Surveys in Ontario indicate buckthorn is a suitable and highly preferred season-long host of BMSB, supporting both nymphs and adults.


For more information:
Toll Free: 1-877-424-1300
E-mail: ag.info.omafra@ontario.ca