Kills Vine Weevil Larvae. Vine Weevils are black beetles about 8mm long with the front part narrower than the back. Eggs are laid near the plant stems from which hatch 8-12mm long, white, horseshoe shaped grubs which stay in the ground between August and early June before hatching into adults.
The adult feeds at night on leaves, making unsightly notches around the edges, hiding during the day. It is the grubs which cause most damage, by feeding on the plant roots over Winter, often completely severing them from the upper stems.