Planthopper family Issidae (Insecta: Hemiptera: Fulgoromorpha): linking molecular phylogeny with classification

A molecular phylogeny of the planthopper family Issidae (Hemiptera, Fulgoroidea) is provided using both Maximum likelihood and Bayesian inference analyses. The phylogeny is based on 18S, two parts of 28S, COXI and Cytb genes from 50 genera and 79 ingroup species (including 8 species recently excluded from Issidae). As with the only few previous studies, an important taxonomic impediment is observed with the sampling; however for the first time, all analyses depict several fully supported lineages, which challenge the recent proposed "modern classification" of the family. It also highlights a strong coherence between these lineages and their respective geographical distribution. All previously excluded taxa are confirmed as not being part of the Issidae as recently defined which monophyly is confirmed. Accordingly, a new classification of the family is proposed with 3 subfamilies and 7 tribes as follows. Neotropical issid Thioniini in Thioniinae stat. rev. is re-established as an independent lineage sister to all other Issidae. Palaearctic Issidae are weakly supported as a monophyletic lineage, Issinae stat. nov., including 2 tribes: Issini stat. nov. (genera Issus and Latissus) and Hysteropterini stat. rev. (all other Palaearctic genera). Oriental Issidae form a strongly supported monophyletic subfamily group Hemisphaeriinae stat. rev. including 4 tribes: Kodaianellini trib. nov., Sarimini trib. nov., Parahiraciini Cheng & Yang, 1991, and Hemisphaeriini Melichar, 1906, the latter including 2 subtribes: Mongolianina s.trib. nov., and Hemisphaeriina Melichar, 1906. A Neotropical lineage including the genus Picumna is provisionally placed in incertae sedis within the Hemisphaeriinae stat. nov.