The Brown Marmorated Stink Bug, A Fall Invasion.

The flat-bodied, thin-legged brown marmorated stink bug (BMSB) invading your home in the fall are now emerging as the weather warms up. As the insect searches to find their way out of your home they become very active, especially as sunlight intensifies and temperatures increase, creating March Madness for homeowners.

This month BMSB will begin moving into the outdoors to forest trees such as Tree of Heaven. Then on to orchards, seeking out newly developing stone fruits such as peaches, cherries, plums, nectarines and apricots.

New efforts by Cornell University scientists to control this household nuisance and agricultural pest is slowly taking hold. This miniscule Samurai Wasp, only 2mm in size, is our superhero in what could be the next Avengers film or David and Goliath story.

Native to Asia, brown marmorated stink bugs (Halyomorpha halys) were first detected in Pennsylvania in the 1990s before spreading throughout the mid-Atlantic states and up the East Coast. In 2010, the right environmental conditions caused their numbers to skyrocket. In New York state, the brown marmorated stink bugs can develop two generations in a single year, one in the spring and another in August, which leads to exponential population growth.

“By 2012, we saw a 20 to 30 percent loss in apple production from the damage caused by brown marmorated stink bugs” in Dutchess, Orange and Ulster counties, said Peter Jentsch, a senior extension associate and director of the Hudson Valley Research Laboratory in Highland, New York.

Samurai wasps (Trissolcus japonicus), native to Asia, are now found in many parts of the United States including NYS. The wasps lay their eggs inside the brown marmorated stink bugs’ eggs, killing developing nymphs and hatching as adult wasps. They have been found to reduce BMSB numbers by 80% in their native range.

“As a biocontrol agent, the wasp is not only very effective at reducing the population of brown marmorated stink bugs, but [it is] the least environmentally damaging of all the options for controlling this pest in both the urban and agricultural system,” Jentsch said.

In 2016, Cornell researchers trapped wild samurai wasps in Marlboro, New York, and reared laboratory colonies. They then released the wasps as a biocontrol agent on 28 farms in 32 agricultural sites throughout New York in Orange, Ulster, Dutchess, Columbia, Wayne, Ontario, Orleans and Monroe counties. They also placed stink bug eggs around the perimeter of orchards and vegetable fields to see if the wasps would parasitize them.

Initial findings revealed survival rate of Samurai wasp after release across the sites surveyed, and wasps parasitized the eggs placed by the researchers in two of the sites. In 2018 the scientists found that the wasp populations survived the winter; with researchers continuing to assess the wasp’s ability to control brown marmorated stink bugs in New York in the years to come.

In addition, researchers are in the process of investigating “attract and kill” stations for homeowners and growers to tackle stink bugs, using a pheromone to attract the bugs to netting embedded with pyrethroid insecticide, which kills them.

Jentsch, along with Art Agnello, professor of entomology at AgriTech in Geneva, New York, created a statewide, county-based map that shows presence and distribution of brown marmorated stink bugs. Using an invasive mapping system, the researchers set traps to see where the stink bugs have passed a threshold of 10 adult insects per trap, used by tree fruit growers as a signal to begin IPM management practices. The system incorporates trap data to create a color-coded map of the presence of brown marmorated stink bugs within each county.

The data also contribute to national stink bug tracking efforts, funded by the United States Department of Agriculture’s Specialty Crop Research Initiative.

“We are trying to generate information of a national as well as a statewide presence in New York,” Jentsch said. “Our March Madness Citizen Science project is designed for homeowners who may be interested in putting their BMSB on the may and acquiring Samurai wasp to control BSB in their neighborhoods.”

A Jentsch Lab blog site also links to a brown marmorated stink bug identification page so user homeowners and farmers can correctly identify the insect before treating their crops.