Big and beautiful: the Megaxyela species (Hymenoptera, Xyelidae) of East Asia and North America

Megaxyela Ashmead, 1898 comprises 13 species, four of which are described as new and one is removed from synonymy: Megaxyela euchroma Blank, Shinohara & Wei sp. nov. from China (Zheijang), M. fulvago Blank, Shinohara & Wei sp. nov. from China (Hunan, Jiangsu, Zhejiang), M. inversa Blank & D.R. Smith sp. nov. from the USA (West Virginia), M. langstoni Ross, 1936 sp. rev. from the eastern USA, and M. pulchra Blank, Shinohara & Sundukov sp. nov. from China (Hubei, Jilin, Liaoning, Shaanxi, Tibet), South Korea (Kangwon-do) and Russia (Primorskiy Kray). The male of M. parki Shinohara, 1992 is described for the first time. A lectotype is designated for M. gigantea Mocsáry, 1909. A cladogram, based on COI sequences of seven species, is presented and interpreted in view of selected morphological characters. Records of M. fulvago sp. nov. from Hunan and of M. pulchra sp. nov. from Tibet extend the known distribution of Megaxyela in the Old World 600 kilometers farther south and 2500 kilometers farther west than previous records.