The three main stages of the SCN life cycle are the egg, juvenile, and adult female. SCN can complete its life cycle in four weeks under ideal conditions (soil temperatures at 75° F)
*All life stages not depicted at same size scale*
Eggs develop into juveniles (J1, J2). The J2's hatch and enter the soybean root to feed and grow. The adult females break through the root surface but remain attached to the root. The males leave the root. Adult males mate with adult females on the root surface. Females then lay 50-100 eggs in an egg mass on their posterior end. Finally, the female fills up with 200 or more eggs. Eventually, the egg-filled female dies and her body wall hardens to form a tough cyst around the eggs.
Click here to watch a flash animation by Dr. Melissa Mitchum of the University of Missouri explaining the SCN life cycle and soybean resistance to the nematode.