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Horticulture and Home Pest News
Horticulture & Home Pest News is filled with articles on current horticulture, plant care, pest management, and common household pests written by Iowa State University Extension specialists in the Departments of Entomology, Horticulture and Plant Pathology.

It's Weevil Time Again

This article was published originally on 7/12/1996

As usual, the imported longhorned weevil and the strawberry root weevil (little insects with long names) are appearing on and in houses as a post-Independence Day surprise. These are the weevils that are often mistakenly described as "ticks crawling on the walls." Upon closer examination they can be readily discerned as insects by the presence of 6 legs and a pair of "elbowed" antennae at the front end.

Both weevils are shaped like a light bulb or pear. The imported longhorned weevil is mottled tan and gray in color while the strawberry root weevil is shiny black. Length for both is about 1/4 inch, though to be more precise, the imported longhorned weevil is 4 mm long and the strawberry root weevil is slightly longer at 6-7 mm.

These weevils are common "accidental invaders" that crawl into houses and buildings from outdoors by mistake. They are harmless; they do not damage the house or furnishings and they cannot bite or sting people or pets. They are merely a nuisance by their presence.

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 malathion, Dursban or diazinon insecticide on and along the foundation and in outdoor areas of weevil abundance may be of some benefit. Adults already inside need only be vacuumed or swept up and discarded. Indoor aerosol insecticides are not very effective.

Outdoors, the weevils, especially the imported longhorned weevils, may cause varying amounts of defoliation on landscape and garden plants. Foliage may appear "notched" at the edges because of feeding by the adults, or flower buds may be fed upon and damaged. The larvae of these weevils are grubs that live in the soil and feed on the small roots of many different plants. Control of the larvae in the soil is not practical nor necessary. Control of adults in the garden may be difficult and minor amounts of leaf feeding should be tolerated rather than resorting to insecticide cover sprays of Sevin, rotenone or malathion.



This article originally appeared in the July 12, 1996 issue, p. 118.

Year of Publication: 
1996
Issue: 
IC-475(18) -- July 12, 1996