Strawberry root weevils: Uninvited guests stop by in late summer and early fall

Strawberry root weevils can be found inside homes this time of year, though they won’t cause any damage to you, your home or pets.

Strawberry root weevil adult. Photo: Pest and Diseases Library, Bugwood.org
Strawberry root weevil adult. Photo: Pest and Diseases Library, Bugwood.org

Strawberry root weevils are a common insect invader that can be found in late summer and early fall walking on walls, cruising across the ceiling and wandering on the floors. This small, one-quarter-inch, dark brown or black insect is pear-shaped and has small, longitudinal grooves on its back that look like a series of tiny, indented spots. Being an insect, it has six legs. The antennae may appear elbowed or bent when viewed from above. Why are these creepies in my really nice house?

It’s just high season for the strawberry root weevil, Otiorhynchus ovatus. These little guys have short snouts that classify them as weevils. Outside, the larvae or juvenile strawberry root weevils feed on the roots of strawberries, evergreens, brambles and many other plants. If plants are being watered, the damage is usually not even noticed. The adults nibble on the edges of foliage, making small notches. Again, damage is hard to find and identify.

The adults are the life stage that comes into the house. Their reasons for a visit are simple and to the point: conditions outside are not comfortable or pleasant. It’s too hot, too cold, too wet or too dry. Their favorite munchies are not available because of the weather events. So they troop inside, hoping that a new location brings better living conditions. They are sometimes found trying to get moisture indoors. While the little herd is inside, strawberry root weevils do not damage the home, pets, food or people. However, they are number one on most people’s “Disgusto-meter.”

Strawberry root weevils are not guaranteed to be a yearly visitor, but if they can get into the house, so can multiple other six- and eight-legged critters. Michigan State University Extension suggest taking a close look at caulking around windows, seeing how tightly screens fit and deciding whether you have good door sweeps – those are the rubbery strips at the bottom of doors that block out light along with insects. The size of the crack or opening does not need to be any wider than the thickness of a credit card. You may see a small opening, but a tiny insect sees an open airplane hangar door.

Strawberry root weevils do not fly, so begin the search for possible entrances low to the ground and work your way up. These house invaders can be vacuumed or swept up, or as a MSU entomologist once said, “Hoover them up."

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