Stink Bug Research

The state of Alabama is home to many pests, and as of 2010 it was introduced to a new one, Halyomorpha halys, a.k.a. the brown marmorated stink bug, or BMSB.

Whenever a new species is introduced, this presents the opportunity for research; For Auburn entomology grad student Savannah Duke ’15, she is doing her part in defending against these insects.

The adult BMSB is shield-shaped and a dark, mottled brown. It ranges in length from 14 to 17 mm, roughly the size of a U.S. dime.

This is because they release a foul smell as a defense mechanism, or when it’s crushed. They have proven to be one of the least appealing prey in the food chain. “The birds won’t even eat them,” Duke said.

Since summer 2015, Duke has been observing their distribution and damage to corn and cotton. She spends most of her time doing field work to conduct this type of research rather than being inside a lab.

Duke has had plenty of experience in working with insects since she began her undergrad in horticulture. While a student worker, she was rearing insects for other peoples’ research and assisted a field scientist during her crop science farm internship with Bayer, a multinational Pharmaceutics company.

According to her 2015-16 study, there are 19 confirmed and four suspected counties that contain the BMSB. “It’s a new invasive species,” said Duke. “It was only discovered in Alabama in 2010 and only came to the US in the 90s.”

She mentions that not knowing of the potential damage they can cause to cotton was why she began the research.

“It may be more of a threat to the older bolls,” she said. “It will stay and continue to feed longer than native stink bugs and this can cause damage that would threaten yields.” The damage these insects can cause to corn is also quite severe. Duke said the BMSB can be devastating in high numbers, but the control practices farmers use against normal stink bugs have so far been effective.

“The part that is new [for] Alabama farmers is knowing what to look for when scouting, and getting the populations under control in a timely manner to prevent heavy (feeding) damage.”

In order to conduct her field work, the grad student did some supplemental outreach and networking with farmers and home owners through social media, as well as with Home Grounds extension agents from the Alabama Cooperative Extension System.

“They start coming out of hiding after winter,” said Duke. “Also, right after the corn starts growing, they start feeding and reproducing. After that they move on to cotton and then soybeans. They find other hosts plants too.”

These stink bugs turn into an urban pest in the fall. The only time you won’t see them is during the winter; this is appropriately called ‘overwintering’.

Another concern with new insects are what diseases it transmits.

Although certain stink bugs can transmit diseases, Duke said that to her knowledge they are not vectoring any at the moment.

When insects end up in new environments, there’s usually speculation to how they got there.

“There’s a lot of theories over how the BMSB made it to Alabama,” she said. “One is trade, like on a shipping container. Another one is a bluegrass festival in Tennessee, in which a lot of people came in RVs from.”

The native origin of these stink bugs’ DNA were traced back to China. “The climate here is fairly similar to their agricultural regions.”

Duke is also involved with the national working group StopBMSB, whose goal is to deliver science-based information about BMSB to the public, free of charge and without advertising. Another is the Southern Region BMSB Working Group, whose overall goal is to assemble the development and implementation of Invasive Pest Management programs.

What may seem like a minor nuisance to our homes can actually have a harmful impact on our agriculture, but research will continue to guide entomologists and farmers alike to controlling these pests in the future.