Imported Longhorned Weevil

Descripiton of imported longhorned weevils

The imported longhorned weevil, like its close relative the strawberry root weevils, is a common "accidental invader" that crawls into houses and buildings from outdoors by mistake. The weevils are harmless; they do not damage the house or furnishings; they can not bite or sting people or pets. They are merely a nuisance by their presence.

Image of imported longhorned weevils
Imported longhorned weevils

Life cycle of imported longhorned weevils

The larvae of the imported longhorned weevils live in the soil and feed on the small roots of many different plants, including aster, clover and turfgrass. They do not cause apparent damage to the plants and control of the larvae in the soil is not practical nor necessary.

Management of imported longhorned weevils

Some of the invasion by longhorned weevils can be prevented by exclusion techniques that close their routes of entry. Look for and seal cracks and gaps through which the adults can crawl into the building. Spraying a residual insecticide labeled for beetle control outdoors on and along the foundation and in outdoor areas of weevil abundance may be of some benefit. For more information on insecticides please see this article.

Image of Dorsal (upper) and lateral views of ILHW showing the characteristic "light bulb" shape.
Dorsal (upper) and lateral views of ILHW showing the characteristic "light bulb" shape.

Adults already inside need only be vacuumed or swept up and discarded. Household aerosol insecticides are not very effective for controlling these weevils.

Do you live in Iowa and have an insect you would like identified?

The Iowa State University Plant & Insect Diagnostic Clinic will identify your insect, provide information on what it eats, life cycle, and if it is a pest the best ways to manage them.  Please see our website for current forms, fees, and instructions on preserving and mailing insects.   

Contact information for each states diagnostic laboratory for U.S. residents.  If you live outside of Iowa please do not submit a sample without contacting the Plant & Insect Diagnostic Clinic.  

Links to this article are strongly encouraged, and this article may be republished without further permission if published as written and if credit is given to the author, Yard and Garden, and Iowa State University Extension and Outreach. If this article is to be used in any other manner, permission from the author is required. This article was originally published on September 12, 2016. The information contained within may not be the most current and accurate depending on when it is accessed.