Latin name: Otiorhynchus sulcatus
Reason for Concern:
1) Predominant caneberry weevil species. Contributes to serious economic loss.
2) Adults which emerge in early May and June, can contaminate machine-harvested fruit.
3) Grubs weaken canes, devour small rootlets, and destroy the bark and cortex of large roots.
Larvae are white or pink, legless, "C"- shaped grubs, about 9 mm long fully grown with distinct brown heads. Found in soil during most of winter and summer. Adults are flightless, hard-shelled beetles, oblong oval, about ½” long, with a broad snout, long, downward curved mouthparts and elbowed antennae. Body is slate gray to blackish-brown and wing covers have many small pits and hairs. They feed at night on foliage and remove large scallops from leaves. Such leaf damage is a good indication that weevils are present but is not economically damaging to the plants. During the day, they hide around the crowns of plants.
Adults (nearly all females) appear after bloom, beginning in May, continuing until after harvest season laying their eggs around the crowns about 1 month after emergence. They can lay up to 200 eggs during their adult lifetime (90-100 days). Eggs hatch in 2 to 3 weeks and larvae burrow into the soil to feed on roots and crowns. In the larval stage, size is the only characteristic that distinguishes one species from another. Larvae grow slowly over summer, molting 5 to 6 times. By late fall, they have matured and are about 5/8” long. They enter a prepupal stage in an earthen cell and pupate the following spring/summer. There is one generation per year. Adults are flightless but very active walkers.