Cysts can then also be found on the skin of the tubers. Each year without host a certain fraction of the eggs will hatch (spontaneous hatch). The eggs can survive for up to 20 years inside these cysts.
Cysts are present on the surface of tubers, and each year without a host, a portion of the eggs will hatch spontaneously. These eggs can remain viable inside these cysts for up to 20 years.