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Column: Western conifer seed bugs moving in for the winter

Nature Watch by John G. Woods
This adult western conifer seed bug is exploring for a place to spend the winter. (John G. Woods photo)

They’re everywhere.

As I look up, I see one crawling across the outside of our glass patio doors.

Another strides across the living room rug with a gait of slow and steady deliberation.

I find 12 more resting on the house siding around the front door.

Almost everyone in the Shuswap knows these little challenges as “stink-bugs.”

They have a well-deserved reputation for smelling very badly if they are disturbed or injured. Entomologists (scientists who study insects) know them as the western conifer seed bug.

Although this is a wonderfully descriptive name, it doesn’t slip easily off the tongue. In fact, the name takes about the same space in newsprint as the bug’s body length in life.

A stink bug’s stink has the same purpose as a skunk’s stink – it’s a chemical defence that they release when provoked. Injure one and you might be reminded of the encounter for an unpleasantly long time.

My go-to procedure is to gently herd the bug onto a piece of paper and then escort it out the door. Most times it will immediately beat a hasty retreat in a buzz of wing beats.

If you take a closer look at the seed bug, you may be surprised that it is about as bizarrely shaped and wonderfully coloured as any animal you may ever see.

Their backs are a study in browns contained in triangles and zigzags dusted with white. Their hind legs sport a bell-bottom flare and the bug’s head is elongated like some alien feat of the imagination.

Overall, the body shape looks just about perfect to tuck into any dark crevice it might choose as its winter home.

Read more: Invasion of the stink bugs: Pest thrives in British Columbia’s warm October

Read more: Agriculture ministry looks for special stink bugs in Salmon Arm and region

True to its official name, they feed on coniferous trees such as Douglas-Fir and Larch in Western Canada and the United States. After the adult seed bugs mate in the spring, the next generation of bugs begins as a row of eggs laid on a host tree’s needle-like leaves.

The eggs hatch and the nymphs soon find a growing seed within a cone. Using their syringe-like mouth parts, the nymphs penetrate the seed and begin the steady process of turning seed sap into bug bodies.

As they grow, the nymphs progress through several stages until they arrive at their adult size and shape and are ready to find a home for the winter. This is the part of their lifecycle that brings us into the story.

Although natural cavities and dark spaces behind tree-bark may be their natural wintering habitat, they readily accept manmade substitutes such as your attic or my shed.

While they do no harm and don’t reproduce in your house, you may not be happy with the invasion. The best solution is to find all the holes and cracks they are using and seal them up. You could consider these tiny invaders as house energy inspectors helping you find where heat is likely to escape during the winter.

That reminds me, my rug-walker has nearly reached the other side of the room. Time to usher it out and make sure I close our doors and windows more tightly.
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