After fertilization, females transform into a spherical pocket of 0.1-0.8 mm across. Hatching, which is favoured by humidity and a substance secreted by the roots of the host plant, is never complete, certain eggs remaining in a latent state for many years. Young juveniles pierce the cuticle of the host plant's radicles, penetrate the tissues and make their way between cells, causing the formation of giant cells which hold up sap circulation. After some time, males vacate the roots while females move to the surface, break out of the epidermis, but with their head remaining fixed to the host. Mating occurs, eggs develop and cause the body of females to swell.
Females then become cysts and die.
These become detached and remain in the soil. The complete cycle lasts 50-70 days. L ife Cycle - There is 1 generation per year. The 1st cysts are few in June but appear in considerable numbers in July and August, formation ceasing in October. D amage - Nematode secretions lead to a modification of plant tissues and a reduction of sap circulation.