Tylenchorynchus spp. Stunt nematodes Damage.  Stunt nematodes are of minor economic importance. Biology.    Tylenchorhynchus are didelphic, medium-sized nematodes.  Ecology.   Stunt nematodes favor sand loam or loam soil, and are widely distributed. Symptoms.  Reduction in host vigour. Damage to other crops.   Some stunting of corn in greenhouse studies has been shown.