Phylogeny, biogeography and morphological evolution of the treehopper-like leafhoppers (Hemiptera: Cicadellidae) Megophthalminae and Ulopinae

Abstract

Recent phylogenetic analyses of anchored-hybrid, transcriptomic and morphological data have consistently recovered a clade comprising the three previously recognized families of treehoppers (Hemiptera), Aetalionidae, Melizoderidae and Membracidae, as well as two groups traditionally included in the leafhopper family Cicadellidae as subfamilies Megophthalminae and Ulopinae. To reconstruct the phylogeny of these two groups of treehopper-like leafhoppers, maximum likelihood and multi-species coalescent analyses were performed on a molecular DNA dataset consisting of ~700 anchored hybrid loci representing 84 terminal taxa. Analyses based on different dataset subsets and approaches yielded largely congruent topologies, although the relationships among Megophthalminae, Ulopinae and treehoppers are still unstable. The monophyly of both subfamilies is strongly supported, but several tribes, including Agalliini, Cephalelini, Megophthalmini and Ulopini, are recovered as non-monophyletic. The origin of Megophthalminae and Ulopinae was estimated as early Cretaceous (~140 million years ago), and the divergence within each subfamily began in the mid-Cretaceous. Continental-scale biogeographic structure is evident in these two groups, with genera occurring on the same continent tending to group together regardless of tribal placement, suggesting that extensive morphological convergence occurred among faunas inhabiting different regions. Ancestral microhabitat reconstruction suggested that megophthalmine and ulopine leafhoppers originally lived on trees or shrubs and later several groups evolved independently to inhabit leaf litter and soil. Convergent modifications of the ocelli, forewings and hindwings accompanied changes in microhabitat preference.