Pieris (Andromeda): Black vine weevil
Photo by: A.L. Antonelli
Biology
Characteristic damage by black vine weevils includes irregular, ragged notching of leaf margins by adults and minor to severe root and bark damage by larvae.
The adult is a gray to black beetle about 2/5″ long which feeds at night. The larvae feed below ground on roots or just beneath the soil surface on the bark at the crown of the plant.
Bark feeding can result in girdling and plant death.
Management Options
See "Using Integrated Pest Management (IPM) in the Landscape" for successful problem management techniques.
Non-chemical Management
Select non-chemical management options as your first choice!
- Hand-pick and kill night-feeding adults.
- Apply beneficial nematodes to kill larvae. The nematodes are most effective when applied as a soil drench in moist soils over 52 F. (late summer to early fall in western Washington). Read and follow all label directions carefully.
Chemical Management
IMPORTANT: Always read and follow label directions when working with pesticides.
For more information on using pesticides visit :
- Apply when first signs of notching on new leaves are noticed.
- Monthly applications may be needed if infestation is heavy.
- Cease when first hard frost occurs in late fall/early winter.
- Night applications are more effective. Beneficial nematodes can be ordered from certain nurseries. They can be applied to control the larval stage if soil temperatures are warmer than 52 F.
- Do not apply nematodes in direct sunlight and be sure soil is saturated with water before application.
Approved Pesticides
If you choose to use a pesticide, some examples of products that are legal in Washington are listed below. Some products are labeled for just INDOOR or just OUTDOOR use, or may allow both uses. Be sure to choose a product appropriate for your situation. Always read and follow all label directions.
WSU Extension programs and employment are available to all without discrimination.
Evidence of noncompliance may be reported through your local Extension office.