Korean oak wilt disease: associated with Raffaelea quercus-mongolicae and transmitted by Platypus koryoensis
Platypus koryoensis is an ambrosia beetle found in forests and native to Korea. Together with its symbiotic fungus Raffaelea quercus-mongolicae (a new fungal species described in 2009), it has been involved in a significant mortality of oak trees (Quercus mongolica) in the Republic of Korea. Korean oak wilt was first observed in 2004 and it is estimated that during 2006-2009, more than 16;000 oak trees have been killed in the Gyeonggi province.
It can be recalled that in Japan, a similar type of association, Platypus quercivorus/Raffaelea quercivora, has also been reported to cause extensive mortality on oak trees (Quercus serrata, Q. crispula) since the 1980s (EPPO RS 2003/067, RS 2007/070). Morphological and phylogenetic studies have showed that R. quercus-mongolicae and R. quercivora are two distinct fungal species. Although different oak species are present in the EPPO region, it seems that the risks presented by the possible emergence of ambrosia beetles and their associated fungi should not be underestimated.
Sources
Kim KH, Choi YJ, Seo ST, Shin HD (2009) Raffaelea quercus-mongolicae sp. nov. associated with Platypus koryoensis on oak in Korea. Mycotaxon 110, 189-197 (abst.).
Lee JS, Haack RA, Choi WI (2011) Attack pattern of Platypus koryoensis (Coleoptera: Curculionidae: Platypodinae) in relation to crown dieback of Mongolian oak in Korea. Environmental Entomology 40(6), 1363-1369.
Moon MJ, Park JG, Oh E, Kim KH (2008) External microstructure of the ambrosia beetle Platypus koryoensis (Coleoptera: Curculionidae: Platypodinae). Entomological Research 38(3), 202-210 (abst.).