Black Vine Weevils are double trouble: There are only female weevils, so every weevil lays eggs.
It last seen in the Vicinity of the northern United States and southern Canada.
Adults chew along leaf edges, leaving characteristic small, scalloped bite marks on the edges. They rarely cause serious harm, but larvae can be very damaging because they feed on roots. Their feeding stunts plants and may indirectly kill them by allowing disease organisms to enter injured roots. Black vine weevils most commonly attack blackberry, blueberry, cranberry, and strawberry plants, as well as some ornamentals, particularly azaleas, camellias, rhododendrons, wisteria, and yews. Potted nursery stock is often attacked.+
Adults are flightless, oval, brownish gray or black snout beetles,” 1⁄3 inch long, with small yellow patches on their backs. Larvae are fat white grubs up to 1⁄2 inch long, with yellowish brown heads. Their tiny white eggs are laid in soil.
Plant resistant rhododendron and azalea cultivars, which have rolled leaf edges that prevent weevils from grasping the edge to feed.
Shake weevils off plants at night onto a drop cloth and destroy them by dropping them into a pail of soapy water.
If leaf damage is severe, cover beds of small plants with floating row covers to stop weevils from reaching the plants to lay eggs.
You can use spray Bacillus thuringiensis var. san diego (BTSD) when adults are feeding on the foliage.
Apply a solution of insect parasitic nematodes (well watered-in) to the soil to control larvae in late spring or early fall.
Intercept adults climbing up shrubs by tying a 6-inch-high band of plastic wrap painted with sticky trap glue around the trunk.
Adults Black Vine Weevil may be controlled a bio control using the fungus Beauveria Bassiana .
Read also: Garden Pest Control