Phylogeny, molecular species delimitation and biogeography of the cryptic subgenus Ulopsina (Hemiptera: Cicadellidae: Ulopinae)

Members of the treehopper-like leafhopper subfamily Ulopinae are widely distributed in the Old World, and many are flightless or flight-limited, making them an ideal model insect group for investigating biogeographical history. The subgenus Ulopsina Dai, Viraktamath & Zhang is endemic to China and is the most speciose subgenus within the genus Ulopsina, which is itself the most speciose genus in the tribe Ulopini. This study presents the first molecular phylogenetic and biogeographical analyses of the subgenus Ulopsina based on one nuclear and three mitochondrial genes. Species delimitation analyses were performed by combining five molecular delimitation methods with morphological evidence. In addition, ecological niche modelling was used to simulate suitable habitat for the subgenus Ulopsina during the Last Glacial Maximum, the Mid-Holocene, the present day and into the future. Our results confirm the status of three described species of the subgenus Ulopsina and support the recognition of three new species: U. (U.) biprocessa Wang & Zhang sp. n., U. (U.) furcata Wang & Zhang sp. n. and U. (U.) serrata Wang & Zhang sp. n. and classified these species into two new species groups (bimaculata and sinica). Dating and historical biogeography analyses indicate that the subgenus Ulopsina likely originated during the early Miocene in Southern Yunnan and Southeast Xizang. Most speciation events in the subgenus Ulopsina occurred in the late Miocene (11.98–7.24 Ma), possibly triggered by several dispersal and vicariance events and influenced by the uplift process of the Qinghai-Tibet Plateau and by climate change. Ecological niche modelling results indicate that the precipitation of warmest quarter and isothermality are two key ecological factors influencing the current distribution pattern of the subgenus Ulopsina. As the climate continues warming, the subgenus Ulopsina may expand northward in subtropical China.