Females. Cyst stage present. Body globose, spheroidal, with a short neck and no terminal cone. Cuticle thick, with superficial lace-like pattern; D-layer present. Vulva terminal, of medium length. Vulval area circumfenestrate; superficial tubercles near vulva. No anal fenestration, but anus and vulva lying both in a “vulval basin.” Underbridge and bullae rarely present. All eggs retained in body (no egg-mass).
Males. Body twisted. Lateral field with four lines. Spicules > 30 um, distally pointed. No cloacal tubus. Tail short, hemispherical
Juveniles 2d stage. Stylet < 30 um. Lateral field with four lines. Oesophageal glands filling body cavity. Tail conical, pointed, with terminal half hyaline. Phasmids punctiform.
Cyst nematodes belonging to the genera Globodera are economically important pests of solanaceous crops. The potato cyst nematodes, G. pallida, and G. rostochiensis are speculated to have originated from South America and have become established in Europe. Limited introductions of G. rostochiensis has occurred to United States and Canada. Because of this, golden nematode, G. rostochiensis, has quarantine status in both the United States and Canada.
Adult female potato cyst nematodes can be discriminated morphologically, however, adult males and juveniles are difficult to identify to species. Given this problem, molecular diagnostic techniques including RAPDs, PCR, and PCR-RFLP have been applied to discriminate potato cyst nematode species.