Nomenclatural changes are provided for Sorbus-feeding Cacopsylla moiwasana (Kuwayama, 1908) species group. Thirteen Palaearctic Cacopsylla species have been recorded from Sorbus L. (Rosaceae), and of these, seven species restricted to East Asia. Among the East Asian species, four Japanese species, i.e. C. elegans Inoue, 2004, C. jezoensis (Miyatake, 1963), C. midoriae (Miyatake, 1963) and C. moiwasana (Kuwayama, 1908), assigned to C. moiwasana species group. Above the latter three species very similar to each other, allopatrically distributed, and all or some of them could be synonymous. The present investigation of the type material resulted in confirmation that Psylla jezoensis and P. midoriae should be treated as junior synonym of P. moiwasana. The following synonyms are proposed: Cacopsylla moiwasana (Kuwayama, 1908) = Psylla jezoensis Miyatake, 1963, syn. nov., Psylla midoriae Miyatake, 1963, syn. nov. The species are newly recorded from Korea.

• Geonho Cho(Laboratory of Insect Biosystematics, Department of Agricultural Biotechnology, Seoul National University, Korea)
• Hiromitsu Inoue(Institute of Fruit Tree and Tea Science, National Agriculture and Food Research Organization (NARO), Akitsu, Higashihiroshima, Hiroshima, Japan)
• Seunghwan Lee(Laboratory of Insect Biosystematics, Department of Agricultural Biotechnology, Seoul National University, Korea, Research Institute of Agriculture and Life Science, Seoul National University, Korea)