Adult vegetable weevils, Listroderes costirostris obliquus, are grayish-brown snout beetles about 1/3 inch long and with a V-shaped light-colored marking near the apex of the elytra (wing covers). The larvae are cream to pale green in color, convex, and about 1/4 to 1/2 inch long when full grown.
Both adult weevils and larvae feed on numerous vegetable crops and weeds. Larvae have long been a minor pest of tobacco, feeding in the plant beds. In 1981, adult weevils were first observed causing damage to young tobacco transplants in the field. Damage may be in the form of stalk damage at or below the soil surface (much like a cutworm), or leaf feeding, or both. Where high populations exist, left untreated, these insects may cause nearly 100% crop destruction.
Only females are known for this species, they being parthenogenetic. Females commonly live for up to two years. Eggs are laid in the crowns of host plants, on leaf petioles, or in the soil near the base of plants from September to March. A female may lay from 300 to 1500 eggs. Larvae feed on foliage and roots, then pupate in earthen cells. There is but one generation a year.
Insecticides are available for control of vegetable weevils both in the plant beds and in the field. Since the list of labeled products is constantly changing, and since available products varies from state to state, there will be no mention of specific products. With all insecticides, read and follow label instructions carefully.
Prepared by Donald G. Manley, Extension Entomologist/Professor, Department of Entomology, Soils, and Plant Sciences, Clemson University.
This information is supplied with the understanding that no discrimination is intended and no endorsement by the Clemson University Cooperative Extension Service is implied. Brand names of pesticides are given as a convenience and are neither an endorsement nor guarantee of the product nor a suggestion that similar products are not effective. Use pesticides only according to the directions on the label. Follow all directions, precautions and restrictions that are listed.
The Clemson University Cooperative Extension Service offers its programs to people of all ages, regardless of race, color, sex, religion, national origin, disability, political beliefs, sexual orientation, marital or family status and is an equal opportunity employer. Clemson University Cooperating with U.S. Department of Agriculture and South Carolina Counties. Issued in Furtherance of Cooperative Extension Work in Agriculture and Home Economics, Acts of May 8 and June 30, 1914.