Influence of temperature on the development of the temperate root-knot nematodes Meloidogyne chitwoodi and M. fallax

Hatching, migration, invasion and post-penetration development of Meloidogyne chitwoodi and M. fallax were examined at 15, 20 and 25 °C. The optimum temperature for hatching of second-stage juveniles (J2) of M. chitwoodi and M. fallax was 20 °C. However, temperatures above 20 °C and no higher than 25 °C were more favourable for hatching of M. chitwoodi than M. fallax J2, which in contrast hatched in greater number at temperatures below 20 °C and no lower than 15 °C. Meloidogyne chitwoodi J2 migrated farther and in higher numbers than those of M. fallax in sand columns. The optimum temperature for migration was 20 °C for M. chitwoodi and 25 °C for M. fallax. Invasion of roots by both nematodes was higher on potato than maize at all temperatures. For both nematodes the degree-days (DD5, base temperature 5 °C) required for completing their life cycle were 555-740 DD5 on potato and 705-740 DD5 on maize. Temperature played a more important role in post-penetration development than the host plant. The behavioural differences found between M. chitwoodi and M. fallax are discussed in relation to different survival strategies of the two species