These insidious houseguests are none other than Halyomorpha halys, better known as brown marmorated stink bugs (BMSB), and you may be hosting them in your own home as I write this. While they’ve only shown up in Ohio over the past few years, the stink bugs have nonetheless spread themselves across the country quickly since their first identification in Pennsylvainia in the late 1990’s. Chances are if you don’t have them in your house yet, you will within a few years’ time.
Brown marmorated stink bugs are native to China, but have spread to other Asian countries as well as North America. Wherever they are located- even in their native range- they are considered a serious agricultural pest. Like all their relatives in the family known as “true bugs,“ the hemipterans, BMSB possess a long, sucking, straw-like tube of a mouth. Across the world, hemipterans feed on a variety of both plant and animal foods. Some bugs are very picky about what they eat. The BMSB is not one of them.
Sucking the juices and soft tissues out of an amazing variety of host plants, the BMSB leaves behind spotty, mushy fruits, vegetables and leaves. The fed-upon plants lose value commercially, rot quicker, and may be subject to the introduction of agricultural diseases spread by the BMSB vector. They are currently considered a mild pest of agricultural and ornamental crops in our state, though they are blamed for more serious losses in states where they have been established for longer.
While we all may feel the indirect consequences of this insect in rising cost of food and nursery plants, many of us will ultimately get up-close and personal with BMSB in the autumn. As temperatures cool, legions of BMSB creep toward our houses, looking for a warm place to spend the winter. They find their way in through any crack or crevice imaginable, and then make themselves at home... in your home.
They’re everywhere in my old, drafty house. On my toothbrush. Falling out of kitchen cupboards. In my clothes. Luckily, the bugs don’t bite, they’re just annoying. And smelly. They don’t call them “stink” bugs for nothin’. Emitting a musky, cherry/cilantro/almond smell when threatened or squashed, these bugs don’t go down without making their presence known. The almond note of their scent comes from traces of cyanide, which is used as a defensive chemical. Some folks suck the bugs up with vacuums, but beware they’ll make your device stink forever. I usually just hand pick and throw them in the toilet. Whatever you do, don’t use pesticides to get rid of them- the danger of dousing your home in chemical poisons far outweighs the annoyance of having the bugs themselves around.
It’s a good thing I’m not scared of insects, because dealing with BMSB gets to be a common, everyday occurrence. A friend of ours (from Pittsburgh, where the bugs have long become established) calls the BMSB “The Great Equalizer” because they are found in everyone’s home, regardless of how rich, poor, urban, suburban, clean, or not that home is. They’re there. For some folks, this is too much to bear. I’ve read accounts of people obsessively duct taping windows and making themselves ill over the need to get a hold of the infestation, with very little success.
The only consolation is that the bugs won’t start new families in your home. When the Spring arrives, BMSB will leave your house as quietly as they entered, where they will mate and lay eggs. The juvenile nymphs will go through five instars, or growth stages, before finally maturing into a dark brown adult about the size of your thumbnail. We have many species of true bugs in Ohio- some are likewise plant pests like the BMSB, while others are carnivorous predators who help keep your garden healthy. So don’t kill indiscriminately- take the time to know which bugs call your yard home. Too often, broad-spectrum pesticide use makes things worse, killing mostly beneficial insects whose absence leaves no natural check on the bad guys.
As for BMSB, scientists and farmers are still trying to rein these critters in by trying a host of integrated pest management techniques. Like so many invasive species, the answers don’t come quickly, easily, or cheaply. In the end, we may just have to get used to yet another foreign pest, and do our best to outsmart them.