The stink bugs have arrived.
Residents all over Greater Cincinnati are complaining of invasions from hundreds of the brown, smelly insects, and these are not your father’s stink bugs. These are Asian invaders sweeping across the country.
Jim Graham, a branch manager with Orkin Pest Control in Cincinnati, said the stink bugs that are taking up residence in local homes creep indoors at a higher rate and in far greater numbers than their North American cousin.
“There is a native stink bug, but that’s not the invasive species that people are seeing by the hundreds,” Graham said. “(The newer species is) the brown marmorated stink bug, which is native to Asia but was imported into this country in the 1990s.”
Like an insect version of snowbirds, northern residents who head south to warmer climates to winter, stink bugs are looking for a cozy place to hibernate during the cold-weather months.
“They’re trying to find a nice, warm, protected area,” said Gene Kritsky, an entomologist at the College of Mount St. Joseph. “They’re finding cracks in walls.”
They are called stink bugs because when threatened or killed they emit a strong odor as a defense mechanism. The odor is most often described as similar to ammonia or cilantro, and sensitivity to the stench among people varies from unnoticeable to almost overpowering.
The reason they show up in large numbers is that when one of them finds a cozy place, it works like a tiny travel agent, emitting another chemical called an aggregation pheromone, to invite his buddies in for the winter.
Unlike bed bugs, another of the region’s home-invading insects, stink bugs don’t pose any real health risks and do not lay eggs or feed indoors. If killed in large numbers, however, they could attract other pests, such as mice or insects that feed off of the carcasses.
The brown marmorated stink bugs, or Halyomorpha halys, are a scourge in several eastern states and are now showing up in increasing numbers in Ohio and Kentucky.
They are about the same size as other native stink bugs but have some distinguishing characteristics, including lighter bands on the antennae and darker bands on the overlapping part of their wings.
Kritsky said the species appeared in this country in 1998 in Allentown, Pa. It is believed the first bugs hitched a ride on cargo transported from somewhere in Asia.
Because this type of stink bug has few predators, and the ones that target them also feed on other insects, the population has exploded in some eastern states.
“In Pennsylvania and New Jersey they’ve been so thick people can shovel them,” Kritsky said.
Now they have started to migrate west.
Graham said his office did not receive any calls about stink bugs two years ago and last year there were just a few. This year, he says, the pace of calls has picked up considerably.
“There are a number of homes we service under a general pest control contract, and we tell customers the best way to combat stink bugs is to keep them outside,” Graham said.
“We tell homeowners to make sure their windows are properly screened and to caulk gaps around doorways or windows.”
The bugs can also slip into a home through window air conditioners, small holes around gas lines and cable television lines or any other tiny crack or crevice.
“They are very flat and about three-quarters of an inch in diameter, so they can fit through a crack that is only about one-sixteenth of an inch,” Graham said.
The bugs usually start coming into homes in September and generally stop once winter hits.
“It usually takes a couple of heavy frosts to kill them off, so people who have them might continue seeing them until late November,” Graham said.
Just because they are out of sight, it doesn’t mean they are out of the house. Unless they are eradicated, there is a good chance residents with an infestation could see the bugs again when they emerge in the spring.
The brown marmorated stink bug is a nuisance to homeowners, but the real threat, if the species continues to grow unchecked, is to crops. The bugs eat fruits and soybeans, and significant crop damage has been reported in some states with infestation.