Globodera rostochiensis

Potato cyst nematodes are parasites causing potato sickness and therefore, are very important from an economic point of view. The juveniles, which just hatched, can be found in the soil searching for a new host.

The picture shows the head of such a juvenile. Characteristic is the heavily developed stylet which is used to pierce the walls of the root cells. This stylet, partly protruded here, has three swellings on which the protractor muscles are attached and which run to the head skeleton, the dark transverse structure just behind the lips. The oesophagus or pharynx, starts just behind the stylet and contains three glands at its basis. One of these glands opens via a duct in the lumen of the oesophagus, just behind the stylet knobs, and causes a bend in the oesophageal lumen. The distance behind the stylet knobs and the opening of the oesopgaeal gland is an important identification character.