Genus Radopholus

The Burrowing Nematode

• 31 species; 2 economically important (R. citrophilis, R. similis)
• causes "spreading decline" of citrus / "toppling" disease of banana, and "pepper yellows" in black pepper
• causes citrus yield reduction in Florida (up to 40-80% per grove)
• quarantine procedures have prevented spread (no damage in California)
• can feed at depths of 10-12 feet
• all stages are infective
• reproduction by parthenogenesis with reports of facultative amphimixis
• very prolific root colonization (2,500/inch of sugarcane roots)
• can migrate from tree to tree through root grafts affected trees have little new growth, foliage loss, smaller fruit
  
• intracellular migration leaves cavities in parenchyma tissue of cortex and stele
• lesions appear on roots after 5-6 days turning brown and cracked in 15-20 days
• some control provided by chemical and fallow barriers

UNL description of quarantine status.