Types

• Black vine weevils are approximately 1/3 inch long. They have blackish-brown bodies and short snouts. Their larvae have creamy-white curved bodies and brown heads. Slugs are soft-bodied, legless, grayish-brown gastropod mollusks, while foliar and root-knot nematodes are microscopic worms.
  
  

Effects

• Adult black vine weevils chew the edges off hosta leaves. Their larvae feed on the roots, causing stunted growth or plant death. Slugs chew small round holes in hosta foliage. Foliar nematodes damage the soft plant tissue between leaf veins, creating yellow or light-green stripes that later turn brown and tear or drop out, resulting in a ragged appearance. Root knot nematodes damage roots while feeding, interfering with the hosta's ability to absorb water and nutrients.
  
  

Prevention/Solution

• Timed applications of pesticides are necessary to control black vine weevil populations. Slugs can be baited into traps; a beer trap is constructed by burying a flat container in soil up to its lip and placing approximately 1/4 inch of beer in the bottom of the container. Slugs, which are attracted to the beer, crawl in and drown. Commercial slug baits are also available, or slugs can be picked off hosta plants by hand. Foliar nematodes require wet leaves to be able to move around, so keeping leaves dry will prevent nematode damage. Root knot nematodes are controlled by increasing the level of organic matter in the soil.