We knew they were here. But not like this. Not all winter.

Indeed, populations of unusual brown stink bugs, the latest overseas invader, are exploding in Lancaster County.

One local exterminator this week declared the smelly, armor-plated bugs to be flying insect public enemy number one, replacing Asian ladybugs and box elder bugs.

"It's amazing. We're in ground zero," says Jim Fish, owner of Kirchner Brothers Termite & Pest Control Service, 2635 Columbia Ave.

"And I haven't found any rhyme or reason to it. One block in a neighborhood might have five houses infested with them but their next-door neighbor hasn't seen one."

Perhaps most maddening of all, while Asian ladybugs, box elder bugs and others of their ilk have mostly retreated since their autumn infiltration into our homes, the stink bugs seem to appear almost daily, even in the depths of winter.

As frustrated and edgy homeowners note, the sizable, shield-shaped bugs seem to materialize out of nowhere, day after day. Suddenly they are just there on a coffee cup or a pillow case — or belly-up on the floor.

"I saw them last year for the first time, but this year I would say there was definitely an explosion," says Alison Eichelberger, a bug expert and collections registrar at the North Museum of Natural History and Science.

"I have seen them literally everywhere. They're in my office as we speak. I toss them down the garbage disposal at home."

One frantic Johnstown resident writes on an Internet bug forum, "I can't sleep at night without itching or constantly turning on the light to check for them."

Adds an equally wide-eyed resident of Myersville, Md.: "They are the ALIENS the government didn't tell us about."

Well, it just seems so.

Marmorated stink bugs — the kind that are showing up in Lancaster County — were first verified in the United States in Allentown in 1998. Natives of Japan, Korea and east China, they may have arrived here on a packing crate.

"Marmorated" means varigated, describing their coloring.

The stink bugs have been found in 25 counties in Pennsylvania so far, as well as a handful of states on the East and West coasts. They first appeared in Lancaster County three years ago but really took off beginning this fall.

They are expected to eventually spread through the United States and southern Canada.

The 5/8-inch bugs, which look similar to native stink bugs, don't bite, sting or destroy wood or fabric. Though major pests to soybean crops and fruit trees in Asia, their potential damage here is still being assessed.

But they do emit an acrid smell if disturbed — local exterminators say it's much better to vacuum up the bugs or to take them outdoors rather than to crush them.

The smell has been variously compared to fermented plants or tung oil. It also has been described as "not as bad as skunk but almost."

Though the odor is overwhelmingly described as nauseating to some degree, some people claim to find the smell of stink bugs agreeable, comparing it to cilantro, fruit juice, pine needles and "Jergens cherry almond old-fashioned lotion."

The very bad news is that if stink bugs are showing up in your home right now, they're already indoors somewhere and there may not be much you can do about them except gather them up.

The worse news is that it's hard to keep them out of your home. They also leave a scent on the places they overwinter, which will attract stink bugs back, year after year. (Though at least they can't reproduce indoors.)

Come fall, stink bugs seek a place to ride out the winter.

"They only need a fraction of an inch of a crack to get into your house," notes Denny Geib, district manager in the Lancaster County office of J.C. Ehrlich Co. exterminators.

Agrees Fish, "They basically can make themselves as thin as a piece of paper."

They get into attics, between storm windows and door frames, and into soffits, siding, roof shingles and eaves, especially on south- and southeast-facing sides.

When it gets warm, as during last week's thaw, or the bugs see a light, thinking it's the sun, they begin moving.

These are adult stink bugs, which can live for several years; they are not newly hatched bugs.

The best defense is to seal your house thoroughly, but that's easier said than done, especially in older homes.

 If you know stink bugs are in your attic or around a window, an exterminator can spray there. But usually, sprays are most effective when applied to the outside of homes and crevices before stink bugs arrive in the fall.

"Other than that, we're just telling them to vacuum them up and throw them out," says Geib.

Warns Fish, "It's going to be a matter of learning to live with them because they're still in the early stages in this area."


Staff writer Ad Crable can be reached at acrable@LNPnews.com or 481-6029.