Raspberries: Root weevils

Root Weevil or Fireworm larvae feed on raspberry or strawberry roots in May, causing wilting and collapse of strawberry plants just prior to and during fruiting and decline in vigor of raspberry plants. Root weevils are the most damaging.

Root weevil larvae can be found in soil surrounding a single plant. They are C-shaped and have no legs, in contrast to grub larva causing similar damage.

A rust-colored, c-shaped larva half burrowed in soil.
Strawberry root weevil (Otiorhynchus ovatus) larva.

Hand holding a small pile of soil containing many white larva. Larva are C-shaped, with orange heads. 9 larva are visible in the soil. Larva are approximately as large as a pinky fingernail.

Root weevil adults  are usually seen in August.

Black insect on leaf. Insect has a wide, oval-shaped abdomen attached to a small, circular throrax and an even smaller, rectangle-shaped head. The abdomen of the beetle is ribbed with many vertical ridges.
Adult strawberry root weevil (Otiorhynchus ovatus)

Fireworms feed on roots of many plants, but generally do not kill them.

Close-up of rust-colored caterpillar on human palm. Larva is smooth and has 12 body segments. Larva bears resemblance to mealworm, and has a tapered head and bottom.
Fireworm (Choristoneura parallela) larva.

 

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