Potato Cyst Nematode Globodera pallida Pale Cyst Nematode

Potato Cyst Nematode Globodera pallida (Pale Cyst Nematode = PCN) & G. rostochiensis (Golden Nematode) Handoo -Globose to spherical in shape -Prominent anterior neck is present -No posterior vulval cone -Mature cysts are colored red-brown to red-gold Cyst wall is elastic when probed gently -Cyst cracks cleanly when probed firmly -Eggs &/or juveniles are often visible inside the cyst PCN cysts in a typical debris field - Cysts are shiny when wet and when illuminated under microscope -Round shape ‘stands out’ against most other objects in the debris field -Intact cysts will float in cold water Webb Compare Globodera (PCN) cysts with two other common cyst nematode species Christopher Hogger, Swiss Federal Research Station for Agroecology and Agriculture, www. forestryimages. org Heterodera avenae Heterodera schachtii (Cereal Cyst Nematode) (Sugarbeet Cyst Nematode) Globodera spp. Craig Webb, Ph. D. USDA-APHIS-PPQ Plant Pathologist – Identifier craig. a. webb@aphis. usda. gov

Potato Cyst Nematode IMPOSTERS * = Discriminating characteristics vs. PCN Cereal cyst nematode Mc. Donald -Shiny in appearance -Similar in color to PCN -*Lemon-shaped cyst* -*Posterior vulval cone present* -*Short/curved neck* Elastic when probed gently - Sugar beet cyst nematode G. Caubel/INRA Rennes -Shiny in appearance -*Tan to brown in color* -*Lemon-shaped cyst* -*Posterior vulval cone present* -Elastic when probed gently Seeds -Some are shiny in appearance -Relatively large in size Some similar in color to PCN -*No neck/eggs/juveniles visible inside* -*Very hard when probed firmly* Mc. Donald Fungal sporocarps (fruiting body) Mc. Donald -*Generally a matte or dull appearance* -*Smaller than PCN (~70 ųm vs ~535 ųm)* -Similar in color to PCN -’Stem’ looks like a neck *Elastic when probed gently but often shatters when probed firmly*