June 25, 2010

Imported longhorned weevil  (Source: UNL Department of Entomology)

Gary Zoubek, UNL Extension Educator in York, reported finding high numbers of imported longhorned weevils gathering on a house in York County.

These small weevils are about 0.2 inches long and mottled gray, with antennae equal to half the body length, and elbowed near the middle.

This insect has occasionally been found damaging soybeans in Nebraska, and they may be locally abundant this year. Eastern Nebraska is the western range of this insect. Adults injure soybeans by consuming leaf tissue and the smaller leaf veins, leaving ragged damage. Typically injury is very localized within the field and doesn’t warrant treatment.

Imported longhorned weevils have one generation per year. Adults are all females and can reproduce without males. They are incapable of flight, which limits their dispersal ability. Larvae feed on the roots of a large variety of cultivated crops and other plants, including alfalfa, clovers, goldenrod and several grass species. In the past we have seen imported longhorned weevils emerging from field edges and migrating into soybean fields.

Bob Wright
Extension Entomologist, Lincoln