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Abstract Host-microbe interactions are intimately linked to eukaryotic evolution, particularly in sap-sucking insects that often rely on obligate microbial symbionts for nutrient provisioning. Cicadas (Cicadidae: Auchenorrhyncha) specialize on xylem fluid and derive many essential amino acids and vitamins from intracellular bacteria or fungi (Hodgkinia,Sulcia, andOphiocordyceps) that are propagated via transmission from mothers to offspring. Despite the beneficial role of these non-gut symbionts in nutrient provisioning, the role of beneficial microbiota within the gut remains unclear. Here, we investigate the relative abundance and impact of host phylogeny and ecology on gut microbial diversity in cicadas using 16S ribosomal RNA gene amplicon sequencing data from 197 wild-collected cicadas and new mitochondrial genomes across 38 New Zealand cicada species, including natural hybrids between one pair of two species. We find low abundance and a lack of phylogenetic structure and hybrid effects but a significant role of elevation in explaining variation in gut microbiota. 

Abstract Periodical cicadas (Hemiptera:Magicicada) have coevolved with obligate bacteriome-inhabiting microbial symbionts, yet little is known about gut microbial symbiont composition or differences in composition among allochronicMagicicadabroods (year classes) which emerge parapatrically or allopatrically in the eastern United States. Here, 16S rRNA amplicon sequencing was performed to determine gut bacterial community profiles of three periodical broods, including II (Connecticut and Virginia, 2013), VI (North Carolina, 2017), and X (Maryland, 2021, and an early emerging nymph collected in Ohio, 2017). Results showed similarities among all nymphal gut microbiomes and between morphologically distinct 17-yearMagicicada, namelyMagicicada septendecim(Broods II and VI) and 17-yearMagicicada cassini(Brood X) providing evidence of a core microbiome, distinct from the microbiome of burrow soil inhabited by the nymphs. Generally, phylaBacteroidetes[Bacteroidota] (> 50% relative abundance),Actinobacteria[Actinomycetota], orProteobacteria[Pseudomonadota] represented the core.Acidobacteriaand generaCupriavidus,Mesorhizobium, andDelftiawere prevalent in nymphs but less frequent in adults. The primary obligate endosymbiont,Sulcia(Bacteroidetes), was dominant amongst core genera detected.Chryseobacteriumwere common in Broods VI and X.Chitinophaga, Arthrobacter, andRenibacteriumwere common in Brood X, andPedobacterwere common to nymphs of Broods II and VI. Further taxonomic assignment of unclassifiedAlphaproteobacteriasequencing reads allowed for detection of multiple copies of theHodgkinia16S rRNA gene, distinguishable as separate operational taxonomic units present simultaneously. As major emergences of the broods examined here occur at 17-year intervals, this study will provide a valuable comparative baseline in this era of a changing climate. 

Abstract Rapid species radiations present difficulties for phylogenetic reconstruction due to lack of phylogenetic information and processes such as deep coalescence/incomplete lineage sorting and hybridization. Phylogenomic data can overcome some of these difficulties. In this study, we use anchored hybrid enrichment (AHE) nuclear phylogenomic data and mitochondrial genomes recovered from AHE bycatch with several concatenated and coalescent approaches to reconstruct the poorly resolved radiation of the New Zealand cicada species in the generaKikihiaDugdale andMaoricicadaDugdale. Compared with previous studies using only three to five Sanger‐sequenced genes, we find increased resolution across our phylogenies, but several branches remain unresolved due to topological conflict among genes. Some nodes that are strongly supported by traditional support measures like bootstraps and posterior probabilities still show significant gene and site concordance conflict. In addition, we find strong mito‐nuclear discordance; likely the result of interspecific hybridization events in the evolutionary history ofKikihiaandMaoricicada. 

Abstract Phylogenetic asymmetry is common throughout the tree of life and results from contrasting patterns of speciation and extinction in the paired descendant lineages of ancestral nodes. On the depauperate side of a node, we find extant ‘relict’ taxa that sit atop long, unbranched lineages. Here, we show that a tiny, pale green, inconspicuous and poorly known cicada in the genus Derotettix, endemic to degraded salt-plain habitats in arid regions of central Argentina, is a relict lineage that is sister to all other modern cicadas. Nuclear and mitochondrial phylogenies of cicadas inferred from probe-based genomic hybrid capture data of both target and non-target loci and a morphological cladogram support this hypothesis. We strengthen this conclusion with genomic data from one of the cicada nutritional bacterial endosymbionts, Sulcia, an ancient and obligate endosymbiont of the larger plant-sucking bugs (Auchenorrhyncha) and an important source of maternally inherited phylogenetic data. We establish Derotettiginae subfam. nov. as a new, monogeneric, fifth cicada subfamily, and compile existing and new data on the distribution, ecology and diet of Derotettix. Our consideration of the palaeoenvironmental literature and host-plant phylogenetics allows us to predict what might have led to the relict status of Derotettix over 100 Myr of habitat change in South America. 

The periodical cicadas of North America (Magicicadaspp.) are well-known for their long life cycles of 13 and 17 years and their mass synchronized emergences. Although periodical cicada life cycles are relatively strict, the biogeographic patterns of periodical cicada broods, or year-classes, indicate that they must undergo some degree of life cycle switching. We present a new map of periodical cicada Brood V, which emerged in 2016, and demonstrate that it consists of at least four distinct parts that span an area in the United States stretching from Ohio to Long Island. We discuss mtDNA haplotype variation in this brood in relation to other periodical cicada broods, noting that different parts of this brood appear to have different origins. We use this information to refine a hypothesis for the formation of periodical cicada broods by 1- and 4-year life cycle jumps.