Adult black vine weevils (3/4 inch long) are large slate-gray to black insects that cannot fly. They have short, broad snouts, bent or “elbowed” antennae and patches of short hairs on their wings. Adults feed at night, damaging plants as they chew small notches in the edges of leaves. During the day, they hide in soil cracks, garden debris and mulch.
Larvae cause the greatest level of injury to plants. They are small (1/2 inch long), white, C-shaped grubs that tunnel through roots as they feed. Leaves will often wilt (even when properly watered) and plants may be stunted or die. Larvae may also girdle the main stem just below the soil line.
Vine Weevil Control
– Remove mulch and other hiding places from around plants and water only when necessary (larvae and adults prefer moist soil).
– As non-flying insects, weevils travel from plant to plant by walking. It stands to reason then, that Tanglefoot Sticky Barrier should form the first line of defense.
– Apply 100% organic Diatomaceous Earth for long-lasting pest protection. Made up of tiny fossilized aquatic organisms, DE kills by scoring an insect’s outer layer as it crawls over the fine powder. Contains no toxic poisons!
– Immature stages of the black vine weevil are particularly vulnerable to attack by beneficial nematodes, especially in potted plants.
– Least-toxic botanical insecticides should be used as a last resort. Derived from plants which have insecticidal properties, these natural pesticides have fewer harmful side effects than synthetic chemicals and break down more quickly in the environment.