Genus Ditylenchus

Ditylenchus (The Stem and Bulb Nematode) migratory endoparasite mainly in shoots diverse feeding habits (can feed on fungi)

Important species:

• D. dipsaci: can infect over 500 plant species
• D. destructor: potato dry rot (mig. endoparasite of underground plant parts)
• D. myceliophagus: fungivore, pest for mushroom industry (France)

Life Cycle and Host-Parasite Interactions

• reproduction by amphimixis (needs males)
• females lay 200-500 eggs which usually hatch in the plant tissue
• all stages are infective, penetration at shoot apical meristem
• migratory feeding leads to cavities in the parenchymous tissue
• pectinase production is speculated in degradation of the middle lamella that results in cell separation and cavity formation during infection
• swelling, galling, stunting, distortion, and necrosis result from serious infection
• small numbers of nematodes are capable of causing serious damage
• no necrosis and little damage is seen in resistant varies with incompatible reactions
• 4th stage juvenile survival stage (up to 23 years)
• produce "Nema Wool" an anhydrobiotic survival structure
• cause galling and distortion to leaves, brown rings in bulbs
• life cycle is 19-23 days at 15 degrees C