Saliva injected into host tissue breaks down cell contents and, in some cases, causes root galls to form. In some nematode species, the female lays eggs singly or in masses either in the roots or soil. The larvae, which are usually similar in appearance to the adults, go through a series of four molts before reaching maturity. Nematode survival, growth, and reproduction are largely dependent on soil moisture, temperature in the soil or host tissues, and the suitability of the host plant. Under ideal conditions, some nematode species can go from eggs to reproducing adults in 3 to 4 weeks while others require 6 to 12 months.
Nematodes survive adverse soil conditions as eggs or larvae.
Populations of damaging nematodes often peak in late summer or early fall. Few nematodes are found on turfgrass root systems in late winter or early spring. Plant parasitic nematodes are found usually at very low levels in all soils. The heaviest nematode injury is found most often on turf grown in well-drained sandy or sandy loam soils. Few nematode problems are seen on turf grown on heavy clay soils.