Common Name: Strawberry Root Weevil
Scientific Name: Otiorhynchus ovatus
Strawberry Root Weevil, Otiorhynchus ovatus, is a very common insect found throughout Prince Edward Island. After developing into adults, some weevil species are attracted to buildings. It appears they do this to seek shelter from unfavorable weather conditions, especially when it is hot and dry.
They are attracted to moisture and are often found in sinks, bathtubs, water basins and similar places These weevils enter buildings by crawling through cracks or openings around foundations, doors, and windows. They do not harm people or pets, or damage buildings or property, or infest food products. They are just a temporary nuisance.
The period from mid-July to mid-August is the time when Islanders will notice these invaders. They are harmless but annoying pests that wander in from outdoors, often in fairly large numbers. These weevils overwinter, in both the adult and larval stages, under trash, in buildings and in old strawberry crowns. The immature or grub stage (larvae) lives on the roots of the host plants.
These weevils are small beetles that possess conspicuous snouts. They are often light-bulb or pear-shaped. The shiny black, hard-shelled adult weevils develop from larvae that live in the soil and feed on the roots of strawberry plants, evergreen trees and shrubs. These weevils are about 1/4 inch long, with rows of pits along their back, they have six legs and a pair of antennae. Legs and antennae seem rather long for the size of the insects, and the antennae have an “elbow” or bend in the middle.
When immature, the legless, grub-like larvae feed on plants. The larvae begin feeding on the roots and crowns as soon as the soil warms in the spring. The larva is a white, legless grub up to 3/8 inch long with a brown head. The body is held in a slightly curved or open-C shaped position.
Signs of Infestation
The overwintering adults emerge from shelter in the spring and feed upon the foliage and berries. When these adults emerge, they sometimes migrate in very large numbers from their breeding places to find new hosts. The wing covers (elytra) are fused together on these weevils and they cannot fly. Thus, they crawl over the ground in large numbers when dispersing. Males are not known and the females reproduce partheno-genetically. The whitish eggs are laid about the roots and crowns of strawberry plants.
Control in the house: Combating strawberry root weevils in the house can be difficult and frustrating. Some of the invasion can be prevented by exclusion techniques that close their routes of entry. Look for the seal cracks and gaps in the foundation and around the windows and doors through which the adults can crawl into the building. Adults already inside need only be vacuumed or swept up and discarded. Household aerosol insecticides are not very effective for controlling these weevils.