MSU Extension Integrated Pest Management

Pest nematodes

Foliar nematodes are extremely small – approximately 0.8 mm long – colorless roundworms. They need a film of moisture to move around.

 
Foliar nematodes enter leaf tissue through the stomates, feeding on new growth and leaf tissues and causing plant stunting, leaf twisting, curling or spotting. They also create blotched or blighted areas on leaves.

Foliar nematodes feed within the plant’s spongy mesophyll and spend most of the growing season in leaves. The nematodes cannot move across main leaf veins while inside the leaf, so infected areas of leaves are bounded by the veins. Foliar nematodes may overwinter on debris and in the crown of plant buds. They may infect a number of herbaceous perennials, including hosta, astilbe and delphinium.

Management

Dispose of all infected plants and plant material. Avoid splashing water on susceptible plants. Selectively remove leaves from plants just expressing symptoms of foliar nematode damage. Insecticides with translaminar properties may be useful in controlling foliar nematodes.

Print a PDF of this page: Foliar nematodes

Back to IPM scouting in herbaceous perennials.