clipper weevil
Beginner
Scientific Name: Anthonomus signatus (Order: Coleoptera, Family: Curculionidae)
Identification
- Attack strawberries and blueberries, as well as raspberry plantings.
- Small, copper-brown beetle with reddish-brown mottling on the back.
- Distinguishing features are its black head and thin, long, curved snout.
- Adult measures approximately 3 mm in length.
- Adult insects clip off or girdle the stems of flower buds in early spring, and buds are left hanging until they brown and fall off.
Often Confused With
Root Weevil
Pieces of debris
Period of Activity
Clipper weevils have one generation per year. Weevils are present on raspberries between May and early summer. Adult weevils overwinter and emerge in early spring. They chew a hole in buds and deposit their eggs inside. The larva develops and emerges as an adult in the early summer. They do not cause damage after flower buds have opened.
Scouting Notes
Look for this pest in May, as flower buds develop. Tap flower clusters over a tray or dish to look for weevils and clipped buds. Observe bud clusters and check for hanging or missing buds. White sticky cards can be hung in the raspberry row to monitor adult presence. Expect more problems in raspberries when strawberries are grown in close proximity, or where field edges are near woods. .
Thresholds
None established.
Management Notes
- When selecting a planting site, avoid areas close to woodlots or hedgerows.
- Avoid planting strawberries nearby.
- Focus monitoring at edges of planting.
- Examine plants before bloom and look for dead or clipped-off buds.
- Control beetles with pre-bloom application of registered insecticide.
- Insecticide applied prebloom for control of raspberry fruitworm may also control clipper weevil.
- Plantings with a history of clipper problems may require a second application.
Advanced
Scientific Name: Anthonomus signatus (Order: Coleoptera, Family: Curculionidae)
Identification
The clipper weevil, also known as the strawberry bud weevil or strawberry clipper weevil, is a small, copper-brown beetle with reddish-brown mottling on the back. Its distinguishing features are its black head and thin, long, curved snout. The adult measures approximately 3 mm in length.
This insect will attack strawberries and blueberries, as well as raspberry plantings. The main damage occurs as the adult insects clip off or girdle the stems of flower buds in early spring. This results in dry buds dangling off the plants and ultimately falling off. The loss in flower buds leads to reduced fruit production.
Often Confused With
Root Weevil - black vine weevil and other root weevils may be present in raspberry foliage. These are much larger than clipper weevils, and are not generally found near flower clusters.
Debris - Clipper weevil adults are rarely noticed. When disturbed they curl up and remain motionless. In this state they can be mistaken for bits of bark or debris.
Biology
Clipper weevils have one generation per year. Adult weevils overwinter in decaying, old plant debris that protects them from the cold, for example, on the forest floor or along fence rows. Once temperatures increase in early spring, they emerge and move on to young, immature flower buds. They feed on the immature pollen by chewing a small hole in the unopened flower bud, using their long, slender snouts. The female clipper weevil deposits a single egg into a mature flower bud and then girdles the stem just a few mm beneath the bud. This causes the bud to dangle and drop off the plant. It takes about 4 to 5 weeks for the larva or grub to develop inside the bud. It then emerges as a fully developed adult in the early summer. During the summer, adult clipper weevils migrate back into wooded or sheltered areas to over-winter.
Period of Activity
The adult weevils are present on raspberries between May and early summer. They do not cause damage after flower buds have opened.
Scouting Notes
Look for this pest in May, as flower buds develop. Tap flower clusters over a tray or dish to look for weevils and clipped buds. Observe bud clusters and check for hanging or missing buds. White sticky cards can be hung in the raspberry row to monitor adult presence. Expect more problems in raspberries when strawberries are grown in close proximity or where field edges are near woods. .
Thresholds
None established.
Management Notes
- When selecting a planting site, avoid areas close to woodlots or hedgerows.
- Avoid planting strawberries nearby.
- Focus monitoring at edges of planting.
- Examine plants before bloom and look for dead or clipped-off buds.
- Control beetles with pre-bloom application of registered insecticide.
- Insecticide applied prebloom for control of raspberry fruitworm may also control clipper weevil.
- Plantings with a history of clipper problems may require a second application.
