Factors Influencing Survival of Ditylenchus dipsaci (Kühn, 1857) in Soil.

Ditylenchus dipsaci larvae survived in soil without a host plant for at least 242 days when held at 15 C and 21 C. Larvae held at 15 C remained infective for 212 days. Moisture levels within both clayey and sandy soils did not appreciably affect recovery of larvae. Active nematodes recovered from soil are not necessarily infective. Temperatures of -12, 0 and 4 C had little adverse effect on larvae in infected leaf tissues in soil. Larvae in soil exposed to 0 C for short periods of time were not affected adversely. Recovery of larvae from sandy soil by Baermann funnels was significantly better at 24 C than at 4 C. Differences in recovery from clay soil were not significant at these temperatures.