Brown marmorated stink bugs are active now!

Hannah Fraser, Entomologist – Horticulture, OMAFRA Guelph

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.  

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 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)

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.