The juvenile penetrates soybean roots and causes the formation of specialized feeding cells in the roots' vascular system. If the juvenile is a male, it leaves the root and moves throughout the soil and probably does not contribute to further plant damage. If the juvenile, however, is a female, it loses the ability to move and swells to a lemon-shape as it matures. The young adult female is called a white female. Plant damage is primarily due to the feeding of females.
White females become yellow as they age and then brown after they die.
The brown stage is the cyst for which the nematode is named. Each cyst can contain up to 500 eggs, but under field conditions, usually fewer. The cyst protects the eggs from adverse conditions in the soil environment. Eggs in the cyst can remain viable for years even in the absence of a suitable host. Host suitability Moisture SCN cannot reproduce without a host plant.