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WSU/Pend Oreille Extension introduced the Sense of Place series in 1999, with a focus on local landscape and natural history of Pend Oreille County, Washington. A partnership with the Kalispel Tribe of Indians Natural Resources Department has allowed us to expand this program through EPA funding to include more classes, a newsletter and this website.


by Carol Mack

They make their first appearance in early fall, these smelly invaders of our houses. They move right in and party all winter long, issuing invitations to their friends via chemical signals. Who owns this house, anyway?

Their frantic buzz and flash of yellow and black are a bit heart-stopping. But they have no stingers, do not spoil our foodstuffs nor destroy our dwellings. When they land, the reddish brown leathery, overlapping wings are evident, and you can see the flattened band on the hindmost legs that puts them in the leaf-footed bug family. And the smell! Most of us call them stink bugs, although entomologists reserve that name for a different family. More accurately, these are Western Conifer Seed Bugs, Leptoglossus occidentalis, “western narrow-tongue,” which they use to suck the juices out of the seeds growing in cones of as many as 30 species of trees. They are considered a pest by foresters - especially in seed orchards where selected trees are maintained for their annual cone crop.

Conifer seed bugs mate and lay their small barrel-shaped eggs on foliage in mid to late spring. They hatch after about 21/2 weeks of development. The immature nymphs then seek out and feed on maturing cones in treetops throughout the summer, becoming adults in late August. As temperatures drop during the fall and early winter, the adults look for a dry over-wintering location where they go into a state of torpor until spring. Favorite spots are under peeled bark and in bird and rodent nests.

Obviously, some of these bugs have higher ambitions for winter lodgings than rodent nests, and choose our houses instead. The warm interior temperatures cause them to be more active and they fly noisily around light fistures or windows, or, one memorable fall visit, my brother-in-law’s shiny bald head. No insecticide is registered for inside use on them. Most advice runs along the lines of preventing entry by sealing cracks around windows and doors. But I’m here to tell you that after 25 years of sustained efforts with a caulking gun, I still can find a couple dozen bugs inside on any given sunny winter day.

My husband once suggested that it might be easier to change my attitude toward the bugs than to successfully fortify our house. Joining in this spin campaign, our kids renamed them “stink friends” and even played with them occasionally. I once looked through the plastic windows of a toy airplane to see at least 30 stink friends milling around - nowadays they’d be locked up for carrying concealed chemical weapons.

That essence-of-green-banana chemical is hexanal, and it functions as an alarm pheremone to communicate the presence of a threat and to repel predators. The threat of unleashing that odor inside certainly deters me from violence. However there are several heroes of our winter woods who eat these bugs with gusto, including flickers, gray and Steller’s jays, chestnut-backed chickadees and hairy woodpeckers. We evict our bugs into the snowbank outside our window where they are immobilized by the cold and provide us entertainment as the birds discover them. Free birdfeed—now there is a positive spin… For mass collecting from those sunny windows, hold a square-sided plastic container firmly to the glass below them and dislodge them with a gentle tap. Some folks find the hand-held vacuum cleaners a nifty solution. Or if you’re feeling brave, grasp firmly by the antenna and fling.

Stink friends were once limited to the Rocky Mountains, but their range seems to be spreading rapidly. Extension offices all the way to New England are starting to get inquiries about these household visitors—and their advice is along the lines of what I dispense: “You have stinkbugs...? Aren’t you lucky to live in a forest!”

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