Northern Utah CWMACooperative Weed Management Area

Biocontrol agents

Hylobius transversovittatus

Biocontrol agent

Biology

Adults emerge in late summer and live for up to 3 years. Adults are 8-12 mm long. Eggs are laid from June – August. Adults lay 1-3 eggs per day. Eggs are deposited in soil and hatch after 11 days. Larval stages may last for 1-2 years.

Destructive Stage

Adult (leaf feeding) and larvae (root mining)

Impact To Host

Larvae mine roots while adults feed on foliage. Small roots can be destroyed within two years while large roots may die after several years of infestation.

Redistribution

Adults are nocturnal and must be collected at night. Night collection can be difficult. Some laboratories rear H. transversovittatus on artificial diets. These are available free by contacting Amber Richman (435-830-4146). Adults can be released on plants or eggs can be released on roots. A typical release is 100-200 weevils. These should be used with Galerucella spp. for maximum control.

Target weeds