Cobweb disease symptoms were observed in a mushroom farm in Buye, Korea during a disease survey in 2008-2011. Five isolates of Cladobotryum sp. were obtained from the infected caps and stipes. These isolates of Cladobotryum sp. were identified as C. mycophilum based on their morphological, cultural characteristics and analysis of the ITS sequences. Early symptoms were noticed as round, fleshy, yellowish brown lesions on mushroom caps. Late symptoms progressed when the parasitic fungus formed white cobweb circular colonies on dead or damaged pinheads, spread on the surface of the casing, and covered entirely fruiting bodies. Optimal temperature and pH for mycelial growth on MEA is 23℃ and 6.0. Microscopically the spores of the fungus are large and most 2~3 celled produced on vertically branched conidiophores. Mushroom caps turned dark brown and shrunk due to soft rot. Testing of sensitivity to selected fungicides showed that isolate was highly resistance to Mancozeb and Thiophanate-methyl, moderately sensitivity to Iprodione, and highly sensitivity to Benomyl, Prochloraz-Mn and Carbendazim.

ABSTRACT
 Disease incidence and symptoms
 Pathogenicity test
 Mycological characteristics
 Internal transcribed spacer (ITS) sequence analysis
 Testing of sensitivity to selected fungicides
 References

• Chan-Jung Lee(Mushroom Research Division, National Institute of Horticultural and Herbal Science, RDA)
• Hye-Su Han( Mushroom Research Division, National Institute of Horticultural and Herbal Science, RDA) | Hye-Su Han
• Chang-Sung Jhune( Mushroom Research Division, National Institute of Horticultural and Herbal Science, RDA) | Chang-Sung Jhune
• Jong-Chun Cheong( Mushroom Research Division, National Institute of Horticultural and Herbal Science, RDA) | Jong-Chun Cheong
• Jin-A Oh( Mushroom Research Division, National Institute of Horticultural and Herbal Science, RDA) | Jin-A Oh
• Won-Sik Kong( Mushroom Research Division, National Institute of Horticultural and Herbal Science, RDA) | Won-Sik Kong