At first we thought they were aliens.

Long spindly legs. An abdomen like a squared-off arrowhead. A sticklike head out of a science fiction movie. They lumbered lonely along countertops then fluttered away in drunken V-trajectories sounding like toy outboard motors.

“Where is it now?”

“Don’t let it land on me.”

“What are these things, anyway?”

This last question worried us because the first time we saw them we had just returned from living in mainland China. What if these things had stowed away in a suitcase in Xiamen, traveled with us to Maine, propagated to tens of thousands, and were going to decimate North America’s ecosystem?

The real shock came when we killed one, which was not hard to do because they move like they have a load in their pants. One paused along a margin of the bay window and I slammed it with a folded-up magazine, hoping it wouldn’t splatter. It didn’t. In fact it did not even seem crushed. It just dropped to the sill among the geraniums. Then came the alarm: It stank. Bad. A sour odor, like pine pitch gone rancid in the refrigerator.

Naturally, we decided they must be stink bugs.

As March labored into April, we saw fewer of them and thought maybe these Chinese stink bugs were unable to adapt to the lengthy Maine cold and died out. Maybe we would not be responsible for an environmental holocaust after all.

We more or less forgot about them. Then in about October, they started appearing again, on couch cushions, bedspreads, my wife’s head. Buzzing in the night. Appearing like lugubrious wraiths on the kitchen table.

We kept calling them stink bugs and avoided killing them. I developed a technique of herding the invader onto a sheet of paper, then flicking it out the door. My wife’s students called them “pine bugs.”

It seemed impossible that I could have lived in Maine (with sojourns in China and the Balkans) for nearly 50 years without noticing a house bug that seemed so common. So I did what every amateur naturalist does in the 21st century – I got on the Internet and looked for pictures.

It turned out they are not a stink bug, but one of its relatives of the order hemiptera, also known as “true bugs,” which includes water striders, damsel bugs, ambush bugs, stilt bugs, assassin bugs, bed bugs, and thread-legged bugs, to name just a few odd ones. The family of true bugs invading our house are coreids, or leaf-footed bugs.

As far as I can tell from the bug Web sites, the cartoon-character species of leaf-foots at our house is the Western conifer seed bug. The reason we never saw them before a few years ago is not because they came from China or Zeta Reticuli, but because they’ve been moving eastward in recent years from their original range around the Rocky Mountains, inspired (it is speculated) by milder winters. They appear in the house during cold weather because they’re looking for a warm place to wait for spring.

They stink when you kill them but they feed on the cones of pines and firs, not human flesh, so they’re harmless to us. Still, it’s unsettling to find one in the chicken soup pot (which I did a couple of weeks ago) or scaling my wife’s shoulder (which I did not tell her, I just hugged her with a sweeping hand, thinking what warmth the bug had brought in that way). What a nuisance.

– DANA WILDE, DWILDE@BANGORDAILYNEWS.NET