Heterodera schachtii

The cycle begins with eggs deposited either in a gelatinous mass or inside a cyst formed from the body of the female. The eggs become embryonated, then molt, forming the first and second larval stages. These can exist within the cyst for several years, however some will exit the cyst every year. Hatching can be stimulated by the presence of the host plant. The J2 (stage two, infective larvae) penetrate the root until they reach the vascular tissue. If the plant is suitable, the larva will release chemicals from the stylet to form a pocket of lysed cells called a syncytium. This will be the larva's food source for the rest of its life. The juveniles then go through a second, third, and fourth (final) molt. The stage 4, and later adult, female is swollen and becomes flask shaped. The male releases from the syncytium, fertilizes the attached female, and leaves the root. The females produce a gelatinous mass in which they lay some of the eggs. The rest of the eggs remain inside the female. As the feeding stops, the female dies, and her body toughens, the cuticle becoming a protective envelope for the eggs.