Mesozoic evolution of cicadas and their origins of vocalization and root feeding.

Extant cicada (Hemiptera: Cicadoidea) includes widely distributed Cicadidae and relictual Tettigarctidae, with fossils ascribed to these two groups based on several distinct, minimally varying morphological differences that define their extant counterparts. However, directly assigning Mesozoic fossils to modern taxa may overlook the role of unique and transitional features provided by fossils in tracking their early evolutionary paths. Here, based on adult and nymphal fossils from mid-Cretaceous Kachin amber of Myanmar, we explore the phylogenetic relationships and morphological disparities of fossil and extant cicadoids. Our results suggest that Cicadidae and Tettigarctidae might have diverged at or by the Middle Jurassic, with morphological evolution possibly shaped by host plant changes. The discovery of tymbal structures and anatomical analysis of adult fossils indicate that mid-Cretaceous cicadas were silent as modern Tettigarctidae or could have produced faint tymbal-related sounds. The discovery of final-instar nymphal and exuviae cicadoid fossils with fossorial forelegs and piercing-sucking mouthparts indicates that they had most likely adopted a subterranean lifestyle by the mid-Cretaceous, occupying the ecological niche of underground feeding on root. Our study traces the morphological, behavioral, and ecological evolution of Cicadoidea from the Mesozoic, emphasizing their adaptive traits and interactions with their living environments.

Redefinition of the cicada tribe Hemidictyini Distant, 1905, status of the tribe Iruanini Boulard, 1993 rev. stat., and the establishment of Hovanini n. tribe and Sapantangini n. tribe (Hemiptera: Cicadidae).

A recent paper by Ruschel Campos (2019) on "leaf-winged" cicadas proposed a significant reorganization of the cicada tribe Hemidictyini Distant, 1905g, including synonymization of the monogeneric tribe Lacetasini Moulds Marshall, 2018 following the results of a cladistic parsimony analysis of morphological characters. In this study, we reconsider and revise the morphological analysis of Ruschel Campos and obtain new genetic data for Hemidictya. We find that their study suffers from a limited taxon sample, inappropriate outgroup selection, and misinterpretation of genitalic characters (uncus vs. claspers). We show that Hemidictyini sensu Ruschel Campos includes members of multiple tribes and subfamilies, and we conclude that some of the taxonomic transfers by Ruschel Campos are not supported. The two most similar and leaf-like cicadas, Hemidictya Burmeister, 1835 (South America) and Hovana Distant, 1905g (Madagascar), are probably not closely related but rather an excellent example of convergent evolution. Lacetasini is not a junior synonym of the Hemidictyini but a distinct part of the Tettigomyiinae Distant, 1905g as originally classified. We return or transfer the genera Lacetas Karsch, 1890, Iruana Distant, 1905g, Bafutalna Boulard, 1993, and Murphyalna Boulard, 2012 to the Lacetasini. With the transfer of all genera of Iruanina Boulard, 1993 and Bafutalnina Boulard, 1993 to Lacetasini and with Lacetas transferred to the Iruanina, Lacetasini n. syn. becomes a subjective junior synonym of Iruanini rev. stat. in the Tettigomyiinae. We assign Hovana to Hovanini n. tribe in the Tettigomyiinae and Sapantanga Distant, 1905g to Sapantangini n. tribe in the Tibicininae Distant, 1905b. We propose that Hemidictyini sensu novo contains only the genus Hemidictya and we assign the tribe to Tibicininae with a revised diagnosis.

Molecular phylogenetics, diversification, and systematics of Tibicen Latreille 1825 and allied cicadas of the tribe Cryptotympanini, with three new genera and emphasis on species from the USA and Canada(Hemiptera: Auchenorrhyncha: Cicadidae).

North America has a diverse cicada fauna with multiple genera from all three Cicadidae subfamilies, yet molecular phylogenetic analyses have been completed only for the well-studied periodical cicadas (Magicicada Davis). The genus Tibicen Latreille, a large group of charismatic species, is in need of such work because morphological patterns suggest multiple groups with complicated relationships to other genera in the tribe Cryptotympanini. In this paper we present a molecular phylogenetic analysis, based on mitochondrial and nuclear DNA, of 35 of the 38 extant USA species and subspecies of the genus Tibicen together with their North American tribal allies (Cornuplura Davis, Cacama Davis), selected Tibicen species from Eurasia, and representatives of other Eurasian and Pacific cryptotympanine genera. This tree shows that Tibicen contains several well-supported clades, one predominating in eastern and central North America and related to Cryptotympana Stål and Raiateana Boulard, another in western North America related to Cacama and Cornuplura, and at least two clades in Eurasia. We also present a morphological cladistic analysis of Tibicen and its close allies based on 27 characters. Character states identified in the cladistic analysis define three new genera, two for North American taxa (Hadoa gen. n. and Neotibicen gen. n.) including several Mexican species, and one for Asian species (Subsolanus gen. n.). Using relaxed molecular clocks and literature-derived mtDNA rate estimates, we estimate the timeframe of diversification of Tibicen clades and find that intergeneric divergence has occurred since the late Eocene, with most extant species within the former Tibicen originating after the mid-Miocene. We review patterns of ecology, behavior, and geography among Tibicen clades in light of the phylogenetic results and note that the study of these insects is still in its early stages. Some Mexican species formerly placed in Tibicen are here transferred to Diceroprocta, following refinement of the definition of that genus.