Globodera rostochiensis Golden nematode Damage to potatoes.  Presence of the golden nematode (Globodera rostochiensis) in potato growing areas preclude the export of potatoes to international markets due to the restrictions imposed by many countries against this pest.  Biology.   Juveniles penetrate host roots where they establish a feeding site, developing into swollen females (cysts). Globodera rostochiensis passes through a yellow stage before darkening into the cyst. Ecology.  Globodera species are widely distributed in potato-growing regions. Symptoms.   Patches of poor growth may occur generally in the crop, sometimes with yellowing, wilting or death of foliage. Potato tubers may be small. At extremely high nematode densities, tubers may become infected, resulting in the appearance of cysts on their surface. Damage to other crops.  Tomatoes and eggplant are also susceptible to damage from G. rostochiensis. Control.  References-Links.  Nemaplex- G. rostochiensis Canadian Food Inspection Agency