June 14, 2017
Brown marmorated stink bugs are active now!
The University of Guelph and OMAFRA are conducting a targeted grower participatory survey for brown marmorated stink bug (BMSB), Halyomorpha halys, in Niagara and in Simcoe as part of a larger project, using pheromone baited traps (Figure 1) and visual surveys in commercial tree fruit and grapes.
Figure 1. Experimental pipe trap baited with commercial Trécé BMSB + green stink bug (Acrosternum hilare) attractants. Other commercial traps and lures are available. (Photo credit Kevin Scaife, University of Guelph)
Since late March, the OMAFRA Agriculture Information Contact Centre has received what I would consider a "typical" number of calls and emails from homeowners reporting overwintering BMSB wandering around indoors, and some have been observed trying to make their way outdoors. However, over the last 10 days or so as the weather has become warm and sunny, over 150 BMSB adults have been collected at one of our hot spots in Hamilton, ON (mostly on a single tree - Venus dogwood - adjacent to a trap). Relative to what we have seen in previous years, that is a rather large number of bugs in one place for this time of year. At this point, we are not sure if those numbers are the result of a larger than normal overwintering population, or a function of the lure combination we are using in 2017. Regardless, those adults are sexually mature and are laying eggs.
We have also found several BMSB adults (Figure 2) in a trap set up on a commercial grape farm in the Niagara-on-the-Lake area, captured over the last week and only shortly after the trap was set up. There is evidence from other regions that BMSB will use grape as a reproductive host, meaning females will lay eggs and the nymphs (Figure 3) will complete their development on the crop. Peach is considered an excellent host for BMSB. Given the abundance of peach and grapes in Niagara, growers and consultants should be on the look-out for signs of this invasive pest in their crops and on host plants in the landscape. So far, we have not heard reports of early stink bug injury in crops (BMSB or other species), but it is not too early to add these insects to your monitoring program for 2017.
Figure 2. Adult BMSB. Note the two white bands on each antenna.
Figure 3. Older BMSB nymphs have a prominent white band on each leg, and white bands may be visible on the antennae.
September 7, 2016- Stink Bug Alert!
Apple growers should be on the look-out for signs of stink bugs in their orchards. In the last few weeks, we have visited orchards in Niagara with fruit showing damage that is characteristic of stink bugs (Figures 1-4). Early injury is easy to overlook (Figures 5 & 6). Don't confuse injury with conditions such as cork spot or bitter pit. Stink bugs usually feed on the stem end and on the sides of the apple, with corky flesh developing immediately under the skin. We have also seen injury in tomatoes (Figure 7).
These insects are mobile and can be frustratingly difficult to find during scouting activities. Traps are available for monitoring purposes. These can be useful for early detection, and potentially for action thresholds. Depending on the lure type, they will trap brown marmorated stink bug (BMSB)(Figure 8) and other species.
In the absence of insect samples, we do not know if BMSB is causing the injury, or if it is another species of stink bug. However, BMSB is established in Niagara and other parts of southern Ontario, and it should be added to monitoring / pest management programs. There is some excellent information on managing BMSB in apples and other crops on the stopBMSB.org website. (Note that the products and / or rates we have registered differ from those listed, see BMSB registrations on the OMAFRA website. Recommendations are provisional and will change as more information about BMSB becomes available.
We are seeing mostly adults at this point in the season. Some of these are starting their movement to overwintering sites, but many are still out there looking for things to feed on. They will likely be active for a few more weeks. As a late-season crop, apples and are at high risk (along with pears, corn, peppers, tomatoes, grapes). Pest pressure is often highest along border areas, especially woody areas with wild hosts.
If you think you have found stink bug injury, or if you have found BMSB in your crop, please drop off a sample of the insect and associated damage at your local OMAFRA office. This pest is new to Ontario and we are still learning about its potential impact in crops.
Figure 1. Two apples, both with stink bug injury. The apple on the right has multiple feeding sites and appears irregular.
Figure 2. Magnification may be required to see the small feeding puncture.
Figure 3. Corking appears immediately under the skin with stink bug injury, versus cork spot (not shown), which may be either circular or diffuse and may be separated from the skin by "healthy" flesh.
Figure 4. Sometimes injury can be hard to diagnose. Closer examination of this apple indicated the injury was likely stink bug.
Figure 5. Recent injury to apple (Photo courtesy of Matt Peters)
Figure 6. Recent injury to apple, multiple stings (Photo courtesy of Matt Peters)
Figure 7. Stink bug injury on tomato
Figure 8. Brown marmorated stink bug adult
August 10, 2016
We continue to find BMSB at our hot spot locations. All life stages are present. BMSB adults and nymphs are very pale when they first moult. The brown pigments take a few hours to develop.
So far, we have not found BMSB infesting any crops. However it has been trapped at some of our agricultural survey locations, and in one case (Niagara), we have collected adults and nymphs in wild hosts adjacent to crops. As numbers are increasing, it is very important to include BMSB and signs of stink bug injury in weekly scouting. In addition, we have confirmed the presence of an established population in Toronto. We have suspected the pest was established there following the identification of BMSB adults indoors over the last few years. Several homeowners have now provided pictures and samples of BMSB nymphs over the last two weeks. These reports have contributed significantly to our knowledge on the distribution of this pest in Ontario.
Fig 1 BMSB adults and nymphs are very pale when they first moult. The brown pigments take a few hours to develop.
July 13, 2016
Last week (July 6th), we reported brown marmorated stink bug numbers were starting to increase at our urban hot spots. The dry, hot weather we've been experiencing appears to be favourable for the growth and development of this pest. We are now finding all life stages, including late instar nymphs - which means we will likely see the first new adults very soon. The host range for this insect is broad. Make sure to monitor for its presence in your crops.
Add brown marmorated stink bug to your scouting program
We are continuing our BMSB survey efforts in 20161, using both traps and visual surveys (Figure 1). Many growers and consultants are taking part in our participatory education program and have set up BMSB traps on their farms this year. These traps are very effective at trapping both adults and nymphs from late June through October (by which time adults will have moved to their overwintering sites).
Figure 1. Map of BMSB finds in Ontario (October 2016). Positives are reported at the county level.
We have been observing overwintering BMSB adults (Figure 2) at our urban "hot spots" since May. In the spring, adults migrate from host to host, feeding for several weeks before they mate and the females begin to lay eggs. Over the last few weeks (mid-June onwards), these adults have been laying eggs (Figure 3), and we are starting to see first and second instar nymphs (Figure 4). There is a degree day model for BMSB, but we have consistently found this pest is ahead of its predicted development by a week or two each year (What does the arrival of nymphs mean? In areas where BMSB is established, the risk for injury is increased. Why? It's a numbers game. Both nymphs and adults can cause crop damage as they feed. Eggs hatch where they have been laid to give rise to resident nymphs. Each female BMSB can lay hundreds of eggs in her lifetime.
Figure 2. Adult BMSB. Look for two white bands on each antenna.
Figure 3. Newly hatched BMSB nymphs.
Figure 4. Congregating second instar nymphs. They will eventually disperse from the egg mass.
Commercially available pheromone traps and lures for BMSB are helpful for detection purposes, and researchers in the US are working on developing action thresholds based on weekly trap catches. However, they are not a substitute for regular scouting in and around the farm. In our survey work, we use a combination of traps, visual estimation, beat samples and sweep net samples, depending on the host and /or crop. We look at both the crop and any preferred landscape hosts along border areas. Look for both BMSB and any suspect injury (Figures 5 and 6).
Figure 5. Stink bug injury close to harvest can take a couple of forms, either distinct depressions with feeding punctures or generalized ones.
Figure 6. The skin under the surface of the fruit will be brown and corky.
The US-based stopBMSB.org group has put together an excellent summary of information and management recommendations on their website. They have also published a ranking of risk to various crops and a guide to managing BMSB in vegetables.
1Funded under the University of Guelph-OMAFRA Partnership Emergency Management Theme "Sustainable Management and Survey for Brown Marmorated Stink Bug in Ontario" (C. Scott Dupree, University of Guelph; T. Gariepy, Agriculture and Agri-Food Canada; and H. Fraser & T. Baute, both with OMAFRA).
For more information:
Toll Free: 1-877-424-1300