The average acre of soil in Kansas contains more than 10 billion of these tiny invertebrates. Following injection of digestive enzymes that are frequently phytotoxic, ingestion of the cell contents occurs. General morphology of a plant-parasitic nematode. Most plant-parasitic nematodes inhabit the soil or plant roots but a few types occupy aboveground parts of plants.
Sting nematodes are migratory ectoparasites that selectively feed on root tips.
Lesion nematodes are migratory endoparasites that feed and lay their eggs in the root cortex. During the growing season, most of the populations will be recovered from roots. Cyst nematodes are sedentary semi-endoparasites. Juveniles and cysts can be recovered from the soil. Root-knot nematodes are sedentary endoparasites.