Stinkbug Update

2010 was the year of the brown marmorated stink bug (BMSB).  Stinkbug related calls to the Franklin County Extension office support desk were far and away the number one subject in 2010.  The Penn State entomology fact sheet on stink bugs received over 19,000 hits in the month of September, 2010 alone.  You tube demonstrations on making your own home made stink bug trap from plastic soda bottles went viral across the internet.  Farmers, fruit, and vegetable growers experienced major losses in their corn, soybean, apple, peach, tomato and pepper crops, with similar impacts on the home gardener. A task force of entomologists, Extension educators, and government officials from USDA and EPA was formed to prioritize research and formulate plans to attack the problem.  Local congressmen became involved to lend their support to growers.  In the spring of 2011, given the large populations of 2010, all signs pointed to another year of even larger populations and everyone was prepared to tackle the problem with an aggressive strategy to combat the invader, potentially risking years of integrated pest management programs.

Instead, they barely seemed to be a problem in our area.  Del Voight, Extension Educator for Agronomy in Adams County recently wrote, “I was primed for more widespread stinkbug issues. We had seen signs from last year that this could be a year to watch for stink bugs.   I can count on my hand the few fields that we had to treat this year as opposed to last season’s widespread outbreak.”  Steve Bogash, Regional Horticulture Educator for Small Fruit and Vegetables also said that only a few of his clients had to conduct spray operation to manage stink bug infestations.   University of Maryland entomologist Galen Dively was quoted recently saying  “Right now we aren’t seeing nearly what we expected.”

So what happened?  No one knows for sure, but the 2011 whacky weather starting with high amounts of moisture in the spring, followed by a long, dry, hot spell in the summer, and back to torrential rains in late summer and fall is one potential explanation.  Dively said “I think it scorched them”.  Stink bug nymphs molt five times before adulthood and are vulnerable to drying—and dying—right after they’ve shed their skins.   Voight speculates, “My feeling is that with the tremendous amount of rainfall that this must have affected the ability of the stink bug to really get a foothold this season to limit widespread infestations to our crops. The lesson here is that pest behavior is really tied to weather and extreme fluctuations as we witnessed with the rain this year.” Other speculations include learned predator behavior by birds, for instance, who may have largely ignored the new, stranger last year, but added it to their menu in 2011.

No one is getting complacent, however.  The task force formed last year has formed a working group that wants to stay one step ahead, and the team met in late November 2011 to share the lessons from this year. “We have so much to learn,” says Tracy Leskey, who organized the group in 2010. “We’re looking at every angle to fight this thing.”  The USDA recently awarded scientists at 10 Land Grant Universities (including Penn State) and research stations a total of $5.7 million dollars to continue the search for answers.