In February, I visited my aunt in Baltimore, Md. and she told me about the latest invasive species to plague the Chesapeake Bay region, brown marmorated stink bugs.
Though I had heard of them, I had never seen one. She saved me a specimen that had met its demise on the windowsill. I was, of course, interested in seeing the stink bug first hand.
While deep in conversation, my aunt all of a sudden exclaimed, "There's one!" A brown marmorated stink bug was maneuvering along the stone fireplace. Since Baltimore was experiencing a BMSB outbreak she had developed eagle eyes for detecting them. "There's another one!" The armored bug was on the ceiling, motionless.
The brown marmorated stink bug is a pest on the move in New York with the potential to impact apple and grapes, among other agricultural crops.
(Photo — Gary Bernon, USDA APHIS, Bugwood.org)
As it turns out, it wasn't surprising to find BMSB in February. Like the Asian ladybird beetles and cluster flies, BMSB congregate in overwintering sites, invading houses and buildings in the fall and staying through the cold winter months, becoming a major nuisance to people. As the name suggests, the stink bug produces an odor when disturbed. I wondered how far BMSB had spread in New York.
I learned that brown marmorated stink bugs are in Long Island, the Hudson Valley and beginning to spread throughout central and western New York. Not just a pest to homeowners, they can also cause severe damage to agricultural crops, affecting primarily fruit and shade trees and other woody ornamentals. Their feeding causes dead areas on leaves and fruit and mild to severe water-soaked lesions.
In Asia, where BMSB are native, they are a significant pest of pear, cherry, peach, apricot, apple and soybean. In the U.S., other hosts include bean, grape and raspberry. That means that apple production in the Champlain Valley and the grape and wine industry in the St. Lawrence, Tug Hill and Oswego regions could be at risk if BMSB populations expand. The dairy industry may also be impacted, as BMSB can become a field crop pest.
The bugs feed on a few of the invasive ornamentals as well, such as honeysuckle and Norway maple and non-natives such as butterfly bush (Buddleia spp.) and Rugosa rose (Rosa rugosa). The wide host range and damage resulting from its feeding make BMSB one to watch.
Like many pests, the BMSB likely made its way to the states as a stowaway in packing crates. They arrived in the late 1990s and are known in several Mid-Atlantic States, and now New York. Adults can fly and thereby expand their range; but, as with many other pests, they can also spread by hitchhiking on vehicles and through commerce.
Surveys are ongoing to detect and monitor this pest and its impact on agriculture; however, because the BMSB initially feeds on common landscape ornamentals, homeowners are likely to be the first to spot new infestations.
Be on the look-out. From June to August, females lay clusters of 20 30 light green, barrel-shaped eggs on the undersides of leaves. The adult BMSB are one-half to two-third inches long and are dark mottled brown. The last two antennal segments have alternating broad light and dark bands. The exposed abdominal edges also have alternating dark and light banding.
The brown marmorated stink bug can easily be confused with common, native grey-brown stink bugs (Brochymena), which are beneficial; however, the native stink bugs lack the alternating light and dark antennal markings and have distinct teeth on the upper part of their thorax (the part of the body between the head and abdomen), whereas on BMSB it is smooth.
Currently there are no viable strategies for controlling BMSB. Homeowners can remove them by hand or suction. Farmers must use an integrated pest management approach. Early detection is key. For assistance with identification, contact your County Cornell Cooperative Extension Office at www.cce.cornell.edu. More information is also online at hudsonvf.cce.cornell.edu/bmsb1.html.
Eye on Invasives is a biweekly column that spotlights a top invader when it is easiest to identify. Hilary Smith directs the Adirondack Park Invasive Plant Program, a partnership program housed at the Adirondack Chapter of The Nature Conservancy in Keene Valley. Find out more about this award-winning program online at www.adkinvasives.com.