Black Vine Weevil , Otiorhynchus sulcatus

The black vine weevil is an introduced European species which now occurs throughout the northern U.S. and Canada. Although not common in Maine, the pest is probably widespread because of movement of infested plant material.

Black vine weevil feeds on more than 100 species of plants. It is a serious pest of nursery, greenhouse and other ornamental crops. Favored hosts include rhododendron, azalea, yew, hemlock, spruce, euonymus, andromeda, grape, strawberry, raspberry, blueberry, cranberry, cyclamen, begonia, and ferns.

While the adult weevils feed on foliage, often resulting in an unsightly appearance, the more serious damage is done by grubs (larval stage), which feed on the roots and may girdle the main stem often killing the plant.

Adults are 3/8" long, oblong-shaped, with a short snout, and elbowed antennae. Their bodies are a dull, slate gray to brownish-black color, and their elytra are grooved and may be marked with yellowish scales. All adults are female and unable to fly. The legless, C-shaped larvae are cream colored with shiny brown heads and measure 5/8" long at maturity. Black vine weevil eggs, which are initially white but turn brown as they mature, are laid in the soil or leaf litter at the base of the affected plant.

There is one generation a year, but adult emergence and egg laying occur over several months. (In greenhouses, adults may continue feeding and laying eggs all winter.) Outdoors, adults usually emerge from the soil beneath host plants from June to August, and will feed nocturnally for 4-6 weeks before depositing viable eggs in the ground. Eggs hatch within 2 weeks and larvae burrow through the soil to begin feeding on roots. Mature larvae overwinter below the frostline and resume feeding on roots as the soil warms in the spring. The most damaging feeding occurs just prior to pupation. Pupation takes place near the soil surface and may last a month or longer before adults emerge.

For more information visit these sites:

UMass Extension
Cornell University News Service
Ontario Ministry of Agriculture
Washington State University

If you suspect European crane fly presence or damage, please contact the Maine Department of Agriculture, (207) 287-3891.

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Black Vine Weevil , Otiorhynchus sulcatus

For more information visit these sites: