Foliar nematodes – Aphelenchoides spp.

Anemone Leaf

Anemone Leaf

Infected Anemone

Infected Anemone

Brunnera Plant

Brunnera Plant

Infected Brunnera Leaf

Infected Brunnera Leaf

Browning Leaf Tips

Browning Leaf Tips

Lily Exhibiting Severe Blight

Lily Exhibiting Severe Blight

Blighted Lily Foliage

Blighted Lily Foliage

Browning Leaf Tips

Browning Leaf Tips

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

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 vains 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, lilium 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.