That familiar sight of summer, the strawberry root weevil, is here again. The Strawberry Root Weevil is a small, hard-shelled, shiny black beetle with a narrow head and thorax and large, round abdomen. An easy way to describe them is "light bulb shaped." A common concern is that this household accidental invader is a tick. Unlike ticks, the Strawberry Root Weevil has 6 legs and a pair of rather long, elbowed antennae.
The Strawberry Root Weevil is very common throughout Iowa. The normal habitat is outdoors where they develop as larvae in the soil, feeding on the roots of strawberry plants, evergreen trees and shrubs. In mid-summer, the adults emerge from the soil. They feed on plant foliage but cause no significant damage to the plants. They would go unnoticed except that large numbers regularly wander into houses by mistake The Strawberry Root Weevil is not damaging to the house or furnishings. They do not harm people or pets, and are a nuisance only by their presence.
Combating strawberry root weevils in the house can be difficult and frustrating. Some of the invasion can be prevented by exclusion techniques that close their routes of entry. Look for and seal cracks and gaps in the foundation and around windows and doors through which the adults can crawl into the building. Spraying malathion, Dursban or diazinon insecticide along the foundation and in outdoor areas of weevil abundance may reduce the number of weevils outside and thereby reduce the number wandering in. Unfortunately, spraying of large areas (at least a 10-foot wide perimeter) and frequent reapplication may be required.
Adults already inside need only be vacuumed or swept up and discarded. Household aerosol insecticides are not very effective for controlling these weevils.
This article originally appeared in the July 25, 1997 issue, p. 121.