Life cycle
Juveniles hatch from eggs and travel through the soil to invade new roots or can remain in the same root as the female. They rely on live roots to feed and reproduce.
Juveniles undergo a series of moults inside the roots until they mature. Females continue to feed within the root, stimulating plant cells to enlarge and form a gall. Females can produce viable eggs without males.
As it grows, the female often breaks through the outer surface of the root so that her rear protrudes. She then lays a large number of eggs into a gelatinous matrix either inside or on the root surface. These eggs hatch immediately or become dormant.
Generation times depend on nematode species, temperature and environmental conditions. Optimal conditions vary between species but the life cycle generally progresses in soil temperatures between 10 and 33°C.
In WA, nematodes generally reproduce more slowly and are less likely to cause a problem in winter than in summer. Irrigation of crops over summer provides the ideal environment for most root-knot nematode species.