Abstract
Raffaelea quercivora, together with ambrosia beetle Platypus quercivorus as a vector, is the causal agent of Japanese oak wilt. P. quercivorus occurs from south to east Asia, including Japan, and is associated with trees in the Fagaceae family. R. quercivora is considered native to Japan, Taiwan, Indonesia, Thailand and Vietnam. In Japan, Quercus serrata and Q. crispula [Q. mongolica] are particularly susceptible to Japanese oak wilt, with high rates of mortality. Although there have been reports of the co-occurrence of R. quercivora and P. quercivorus outside of Japan, tree mortality caused by this species complex has never been recorded in these cases. R. quercivora is not on an alert list or listed as a regulated pest in any part of its native range. Although R. quercivora/P. quercivorus are not considered invasive, if they were introduced into susceptible oak forests, possibly via international transport of wood products, there is potential for them to cause extensive tree mortality in other geographic regions.
Genetic variation among Japanese populations of Platypus quercivorus (Coleoptera: Platypodidae), an insect vector of Japanese oak wilt disease, based on partial sequence of nuclear 28S rDNA
