Blueberry Blossom Weevil

Blueberry Blossom Weevils are dark reddish beetles.

Blueberry Blossom Weevils, also called Cranberry Weevils, are dark reddish beetles with white flecks on their wing covers (elytra). Each weevil has a snout nose. Blueberry Blossom Weevils overwinter in wooded areas near fields and move to blueberry bushes as early as bud swell. There is typically one generation per year in blueberry fields. This pest is most common in eastern North America.

Facts:

  • Adults are between 1/16 and 1/8 inch long.
  • Adults are dark brown or black in color.
  • Eggs are laid on flowers, and the grubs eat the flowering parts.
  • Blueberry Blossom Weevils drop to the ground when disturbed.
  • Blueberry Blossom Weevils move off plants if temperatures drop.
  • Feeding can occur as buds expand, but most injury occurs as flower buds open.
  • Commonly found on black huckleberry, wild and cultivated blueberry, cranberry, swamp sweetbells, staggerbush, dangleberry, sheep laurel, swamp honeysuckle and on the flowers of chokeberry.
  • Adults overwinter in sheltered areas.
  • Difficult to control.

 

Female blueberry blossom weevils drill holes into flower buds, before laying eggs into each drilled flower.

Damage:

  • Female drills a hole into the flower buds, before laying an egg into each drilled flower.
  • A small, legless, yellow-white grub with a brown head develops and feeds inside the flower bud, preventing flowering.
  • Injured buds drop to the ground, where the larvae grow and, then, pupate.
  • Adults develop in late spring and may feed on foliage, leaving small puncture marks.

Scouting:

  • Collect weevils from blueberry bushes with a sweep net, or
  • Shake from the foliage onto a white ground cloth.

Control:

  • Some states have low populations that may be controlled by using cultural controls such as clean cultivation of a blueberry field.
  • Check with your local Cooperative Extension Service office for chemicals registered in your area to use for control.

Sources:

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