In general, nematodes reproduce when females lay eggs inside or outside plants where they have been feeding. With some species of nematodes, single females can lay several hundred eggs. The eggs have a tough membrane that aids survival over winter or long dry periods. The eggs hatch into juveniles which, like adults of some species, can feed upon and damage plants. Juvenile nematodes mature and the adult females lay more eggs, thus increasing the population.
Plants are more likely to be damaged as nematode populations increase.
Because of their small size, nematodes rarely move more than a few feet each year by themselves. Consequently, they usually are spread from one area to another in infested soil clinging to cultivation equipment, in soil moved by water or wind, and on roots of transplants. Nematode injury reduces the plant roots ability to take up and transport water and nutrients from the soil. For that reason, the most frequently observed symptoms are nutrient and drought related symptoms. Typical above-ground symptoms are general stunting, yellowing, loss of vigor, general decline, and even death if infestations are severe.