From modern to classic: Classification of the planthopper family Issidae (Hemiptera, Auchenorrhyncha, Fulgoroidea) derived from a total-evidence phylogeny

The Issidae are highly diverse in terms of morphology and species richness. Despite recent efforts, the internal phylogeny and classification of this planthopper family remain controversial. Here, we present a phylogeny of the family inferred with Bayesian and Maximum Likelihood analyses of a nine-gene molecular dataset (4702 bp) and morphological data (35 characters) across a broad sample of taxa (99 terminals). Based on these results, we verify the taxonomic status of the issid subfamilies, tribes and generic complexes. Results revealed a well-supported basal dichotomy of the family into two clades, corresponding to the subfamilies Issinae and Hysteropterinae. Within Issinae, the tribes Issini, Thioniini, Sarimini, Hemisphaeriini, Parahiraciini and Kodaianellini were recovered with high support. Four strongly statistically supported clades were revealed within the subfamily Hysteropterinae, but we refrain from taxonomic decisions in the absence of morphological characters to diagnose the clades A-C. Interestingly, the obtained results are in good agreement with L. Melichar's view on Issidae classification suggested more than a century ago. Our results challenge an early Cretaceous origin of the Issidae and the basal split of the family between Neotropical taxa (Thioniini) and the remaining issids.

Automated summary

The Issidae, a highly diverse planthopper family, has been the subject of controversy in terms of internal phylogeny and classification. In this study, a phylogeny of the family was inferred using molecular and morphological data. The results validated the taxonomic status of subfamilies, tribes, and generic complexes, and revealed interesting insights about the origin and split of the family.