New species and new records of Tullbergiidae (Arthropoda, Hexapoda, Collembola, Poduromorpha) from Xizang, Southwest China, with genetic distance analysis within the family

The Tullbergiidae of Xizang, Southwest China, are studied based on specimens newly collected in 2024. Metaphorura alticola sp. nov ., which was discovered in two localities at extremely high altitudes of 4000–5300 m in Shannan City, is described and illustrated. It can be distinguished from the similar M. motuoensis Bu & Gao, 2017 by the dorsal chaetotaxy, number of vesicles on PAO, and the shape of anal spines on Abd. VI, as well as the large genetic distance of the COI gene. Mesaphorura macrochaeta Rusek, 1976, found from several localities in Xizang, is recorded in China for the first time, and Chinese specimens are described and illustrated. In addition, the distributions for M. hylophila Rusek, 1982, M. krausbaueri (Börner, 1901), M. pacifica Rusek, 1976, and M. yosii (Rusek, 1967) in Xizang are updated according to the newly collected material. DNA barcodes of mitochondrial COI gene for Metaphorura alticola sp. nov ., M. macrochaeta , and M. hylophila are newly sequenced and analyzed together with 26 sequences of the family extracted from GenBank. The genetic distances of different levels in the family Tullbergiidae are analysed. A key for all tullbergiid species recorded in Xizang and a map of their distributions are also provided.