Poplar and Willow Borer Weevil
- adults: ~ 5/16 – 3/8 inch; long snout; black with white/brown markings; resemble bird feces
- larvae: up to 5/16 inch long; white grubs without legs; brown head capsule
Host Plants, Diet & Damage
- primarily willow; poplar
- young/newly planted trees preferred
- damage typically occurs on the lower stem
- adults cause minor chewing injury on stems and shoots
- larvae feed on inner bark into the sapwood
- frass is pushed out from the entrance holes
- cause deformation and weakness of branches and stems
- smaller diameter trees can be killed
Biology, Life Cycle & Damaging Life Stage
- overwinter as larvae in the sapwood
- larvae resume feeding in the spring
- pupate under the bark around May
- adults present from May to mid-July
- one generation per year
- larvae are the primary damaging stage
- Manage trees to improve or maintain overall health.
- Remove and destroy infested plant material.
- Apply an insecticide (carbamate; pyrethroid) to the main stem May through mid-July.