The East Asian Xyela species (Hymenoptera: Xyelidae) associated with Japanese Red Pine (Pinus densiflora; Pinaceae) and their distribution history

Abstract

AbstractThe association of five East Asian species of Xyela Dalman, 1819 with Pinus densiflora Siebold & Zuccarini, 1842 has been demonstrated by the identification of reared adults or of adults collected by emergence traps. The host plant of X. japonica Rohwer, 1910 is doubtful. These Xyela species occur as sibling species or at least as pairs of morphologically similar species, which are distributed vicariantly on the East Asian mainland and in Japan, respectively. The vicariance events for the Korean-Japanese species pairs date back to the disconnection of ancient Japan and South-East Asia during the Mindel-Riss interglacial period (320,000-180,000 BP). The most southern record of a xyelid sawfly from South-East Asia is reported for an unidentified Xyela female from southern Vietnam. Xyela densiflorae Blank & Shinohara (South Korea), X. occidentalis Blank & Shinohara (northeastern China, South Korea), Xyela par Blank & Shinohara (South Korea), and X. tecta Blank & Shinohara (Japan) are described. X. variegata Rohwer, 1910, formerly regarded as a synonym of X. julii (Brébisson, 1818), is reestablished. The male of X. japonica is described for the first time. A key for the identification of these species is presented.