The black vine weevil feeds on numerous outdoor and greenhouse plants. The young larvae feed on small roots. As they mature, they entirely devour larger roots or cut them off. Large larvae also may bore into crowns or corms. Infested plants suddenly wilt and die because of lack of roots.
Adults feed at night and notch foliage and flowers.
In the greenhouse the black vine weevil may have 2 generations each year. Eggs are laid in the soil and hatch in 15 to 21 days. Larvae feed for 3 to 4 months before pupating. The pupal cell is formed I to 2 inches below the soil surface. The pupal period lasts about 18 days.