Adult black vine weevils are 7-10 mm in size, arebrown-black with pale yellow spots on the back and cannot fly. Larvae have a white body and a brown head. Larvae can be found in the soil during April–May and develop into pupae around April–June. The adult weevils can be found above ground from end May to early August. They are mostly nocturnal and hide during the day. They feed from the edge of leaves with characteristic small round bites. Adult black vine weevils deposit eggs back in the soil from July until September. Larvae will hatch from the eggs and will overwinter in the soil. In greenhouses, multiple generations occur. Places with minimum temperatures of 15° C are suitable for overwintering for black vine weevils. 

Black vine weevil damage

Adult weevils cause feeding damage, which is mostly considered as cosmetic damage. It can be recognized as round bites from the leaf edges. Larvae feed from plant roots. When they emerge from the eggs, larvae will start feeding from the smallest roots. As they grow larger, larger roots, root tubers, rhizomes and even bark of woody stems are consumed. A plant with a damaged rootsystem is weakened and extra vulnerable for secondary diseases, like for example fungi. With heavy infestations plants wither and die.