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Ants are abundant, diverse, and occupy nearly all habitats and regions of the world. Previous work has demonstrated that ant diversification coincided with the rise of the angiosperms, and that several plant traits evolved as ants began to expand their nesting and foraging habits. In this study, we investigate whether associations with plants enabled niche expansion and are linked to climatic niche evolution in ants. Our analysis of over 1,400 ant species reveals that ancestral expansion from forest floors into the canopy and out into non-forested habitats closely followed evolutionary innovations in angiosperms. Several Paleogene-Neogene ant lineages independently diversified in non-forested habitats on multiple continents, tracking the evolution and expansion of elaiosome-bearing and arid-adapted angiosperms. The evolution of arboreal nesting tracked shifts in angiosperm physiology associated with the onset of everwet tropical rainforests, and climatic optima and rates of climatic niche evolution were linked to nesting location, with arboreally nesting groups having warmer and less seasonal climatic optima, and lower rates of climatic niche evolution. Our work further underscores the varied paths by which niche diversification occurred in ants, and how angiosperms influenced the ecological and evolutionary trajectories of interacting lineages.

Eusocial insects are characterized by several traits, including reproductive division of labor and caste polymorphisms, which likely modulate genome evolution. Concomitantly, evolution may act on specific genes and pathways underlying these novel, sociality-associated phenotypes. Reproductive division of labor should increase the magnitude of genetic drift and reduce the efficacy of selection by reducing effective population size. Caste polymorphism has been associated with relaxed selection, and may facilitate directional selection on caste-specific genes. Here, we use comparative analyses of 22 ant genomes to test how reproductive division of labor and worker polymorphism influence positive selection and selection intensity across the genome. Our results demonstrate that worker reproductive capacity is associated with a reduction in the degree of relaxed selection, but is not associated with any significant change to positive selection. We find decreases in positive selection in species with polymorphic workers, but no increase in degree of relaxed selection. Finally, we explore evolutionary patterns in specific candidate genes associated with our focal traits in eusocial insects. Two oocyte patterning genes previously implicated in worker sterility evolve under intensified selection in species with reproductive workers. Behavioral caste genes generally experience relaxed selection associated with worker polymorphism, while vestigial and spalt, both associated with soldier development in Pheidole ants, experience intensified selection in worker polymorphic species. These findings expand our understanding of the genetic mechanisms underlying elaborations of sociality. The impacts of reproductive division of labor and caste polymorphisms on specific genes illuminate those genes’ roles in generating complex eusocial phenotypes.

Most ant species have lost the ability to spin cocoons. To explore the evolution of cocoon loss within Formicidae, we perform an ancestral state reconstruction of cocooned pupae across a genus-level phylogeny and use a sister clade analysis to determine the impact of cocoon evolution on ant speciation. Then, we fit models of correlated evolution between cocoon status and several other organismal traits. We find that the re-emergence of cocoons is rare and that “naked” lineages display an increased rate of speciation in 5 out of 9 sister group comparisons. Models of correlated evolution with cocoon status were favored for metapleural gland and worker polymorphism. Metapleural gland favored rates of evolution were inconclusive, while worker polymorphism displayed a higher transition rate towards polymorphism coupled with cocoon loss. These results suggest that cocoon loss may allow for other complex traits to develop and may represent a novel example of relaxed selection.

Background To understand the patterns of biodiversity it is important to consider symbiotic interactions as they can shape animal evolution. In several ant genera symbiotic interactions with microbial communities have been shown to have profound impacts for the host. For example, we know that for Camponotini the gut community can upgrade the host’s diet and is shaped by development and colony interactions. However, what is true for one ant group may not be true for another. For the microbial communities that have been examined across ants we see variation in the diversity, host factors that structure these communities, and the function these microbes provide for the host. In the herbivorous turtle ants (Cephalotes) their stable symbiotic interactions with gut bacteria have persisted for 50 million years with the gut bacteria synthesizing essential amino acids that are used by the host. Although we know the function for some of these turtle ant-associated bacteria there are still many open questions. Results In the present study we examined microbial community diversity (16S rRNA and 18S rRNA amplicons) of more than 75 species of turtle ants across different geographic locations and in the context of the host’s phylogenetic history. Our results show (1) that belonging to a certain species and biogeographic regions are relevant to structuring the microbial community of turtle ants; (2) both bacterial and eukaryotic communities demonstrated correlations and cooccurrence within the ant host; (3) within the core bacterial community, Burkholderiaceae bacterial lineage were the only group that showed strong patterns of codiversification with the host, which is remarkable since the core bacterial community is stable and persistent. Conclusions We concluded that for the turtle ants there is a diverse and evolutionarily stable core bacterial community, which leads to interesting questions about what microbial or host factors influence when these partner histories become evolutionarily intertwined.

Wolbachia is one of the most common intracellular symbionts among insects, but the function of this infection and its effects on the host still remain largely unknown for many taxa. In the case of many social insects, living in colonies results in close interactions, facilitating the dispersion of the symbiont. However, having only one caste responsible for reproduction (queens) could restrict infections. Several groups of social insects have been reported to be highly infected with these symbionts. However, Wolbachia associations across social and closely related non-social insects in a comparative framework has not been examined to date, which may help us understand the role social behavior, geography, and ecology plays in structuring this association. Since 2006 the Multi-Locus Sequencing Type (MLST) approach has been shown to be appropriate for diversity studies, which consists of sequencing five genes spread across the Wolbachia genome. Over the past 15 yr, studies using this approach have been conducted worldwide and have generated large volumes of data. In this review article, we intend to produce a meta-analysis by combining MLST data from across social insects (ants, bees, termites, wasps) and beyond, together with their closest relatives to better elucidate the patterns behind the diversity of this symbiotic interaction. Our main findings reveal that the diversity of Wolbachia (supergroups) is correlated with the host insect taxonomy, biogeography, and social/solitary behavior. In addition, solitary insects such as bees and wasps can interact with a greater diversity of Wolbachia supergroup compared to their social representatives.

Diversidade e inclusao na ciencia sao questoes que ainda precisam ser abordadas e a comunidade cientifica deve agir com urgencia para superar as disparidades, especialmente porque mulheres ainda estao subrrepresentadas nos campos da ciencia, tecnologia, engenharia e matematica (STEM). Informacoes sobre mulheres que escrevem artigos cientificos sao dados importantes e podem nos ajudar a entender se um campo especifico e inclusivo. Focamos na area da Mirmecologia e investigamos se a primeira e a ultima autoria sao tendenciosas nesse campo. Este estudo mostrou que, embora a pesquisa se concentre em um grupo dominado por femeas (formigas), em termos de autoria de artigos cientificos ainda se trata de uma sociedade dominada por homens, sem aumentos significativos na representacao feminina desde 1990, com apenas 35,59% como primeiras autoras e 22,90% como ultimas autoras. Apesar de os dados mostrarem tendencias promissoras dos ultimos anos (2016-2018), com ligeiro aumento de mulheres como primeiras autoras, para a ultima autoria ainda nao houve mudancas. Tambem comparamos os resultados mundiais com os mirmecologistas do Brasil, que e um centro de referencia em pesquisas com formigas. Concluimos nosso estudo propondo varias acoes que todos podemos fazer para superar esse problema e tornar a ciencia mais igual e inclusiva.

A key focus of ecologists is explaining the origin and maintenance of morphological diversity and its association with ecological success. We investigate potential benefits and costs of a common and varied morphological trait, cuticular spines, for foraging behavior, interspecific competition, and predator–prey interactions in naturally co‐occurring spiny ants (Hymenoptera: Formicidae: Polyrhachis) in an experimental setting. We expect that a defensive trait like spines might be associated with more conspicuous foraging, a greater number of workers sent out to forage, and potentially increased competitive ability. Alternatively, consistent with the ecological trade‐off hypothesis, we expect that investment in spines for antipredator defense might be negatively correlated with these other ecological traits. We find little evidence for any costs to ecological traits, instead finding that species with longer spines either outperform or do not differ from species with shorter spines for all tested metrics, including resource discovery rate and foraging effort as well as competitive ability and antipredator defense. Spines appear to confer broad antipredator benefits and serve as a form of defense with undetectable costs to key ecological abilities like resource foraging and competitive ability, providing an explanation for both the ecological success of the study genus and the large number of evolutionary origins of this trait across all ants. This study also provides a rare quantitative empirical test of ecological effects related to a morphological trait in ants., We investigate potential benefits and costs of a common and varied morphological trait, cuticular spines, for foraging behavior, interspecific competition, and predator–prey interactions in naturally co‐occurring spiny ants (Hymenoptera: Formicidae: Polyrhachis) in an experimental setting. We find little evidence for any costs to ecological traits, instead finding that species with longer spines either outperform or do not differ from species with shorter spines for all tested metrics, including resource discovery rate and foraging effort as well as competitive ability and antipredator defense. These results suggest that spines promote broad ecological success in this hyperdiverse group of insects.

Recent advances in phylogenomics allow for the use of large amounts of genetic information in phylogenetic inference. Ideally, the increased resolution and accuracy of such inferences facilitate improved understanding of macroevolutionary processes. Here, we integrate ultraconserved elements (UCEs) with fossil and biogeographic range data to explore diversification and geographic range evolution in the diverse turtle ant genus Cephalotes Latreille, 1802 (Hymenoptera: Formicidae). We focus on the potential role of the uplift of the Panamanian land bridge and the putative ephemeral GAARlandia land bridge linking South America and the Antilles in shaping evolution in this group. Our phylogenetic analyses provide new resolution to the backbone of the turtle ant phylogeny. We further found that most geographic range shifts between South America and Central America regions were temporally consistent with the development of the Panamanian land bridge, while we did not find support for the GAARlandia land bridge. Additionally, we did not infer any shifts in diversification rates associated with our focal land bridges, or any other historical events (we inferred a single diversification rate regime across the genus). Our findings highlight the impact of the Panamanian land bridge for Cephalotes geographic range evolution as well as the influence of taxonomic sampling on macroevolutionary inferences.

BackgroundGut microbiomes can vary across development, a pattern often found for insects with complete metamorphosis. With varying nutritional need and distinct opportunities for microbial acquisition, questions arise as to how such ‘holometabolous’ insects retain helpful microbes at larval and adult stages. Ants are an intriguing system for such study. In a number of lineages adults digest only liquid food sources, while larvae digest solid foods. Like some other social insects, workers and soldiers of some ant species engage in oral-anal trophallaxes, enabling microbial transfer among siblings. But do queens, the typical colony founding caste, obtain symbionts through such transfer? Does this enable transgenerational symbiont passage? And does the resulting partner fidelity promote the evolution of beneficial symbionts? Furthermore, how might such adult-centric biology shape larval microbiomes? To address these questions, we characterized symbiotic gut bacteria across 13 species of Cephalotes turtle ants, with up to 40-million years of divergence. Adding to the prior focus on workers we, here, study underexplored castes and stages including queens, soldiers, and larvae, by performing 16S rRNA qPCR, amplicon sequencing, and phylogenetic classification. ResultsWe show that adult microbiomes are conserved across species and largely across castes. Nearly 95% of the bacteria in adults have, thus far, been found only in Cephalotes ants. Furthermore, the microbiomes from most adults exhibit phylosymbiosis, a trend in which microbiome community similarity recapitulates patterns of host relatedness. Additionally, an abundant, adult-enriched symbiont cospeciates with some Cephalotes. Evidence here suggests that these partner fidelity patterns extend from transgenerational symbiont transfer through alate gyne dispersal and subsequent colony-founding by queens. Like adults, larvae of Cephalotes species exhibit strong microbiome conservation. Phylosymbiosis patterns are weaker, however, with further evidence elevating environmental filtering as a primary mechanism behind such conservation. Specifically, while adult-enriched symbionts are found in most larvae, symbionts of older larvae are highly related to free-living bacteria from the Enterobacteriaceae, Lactobacillales, and Actinobacteria. ConclusionsOur findings suggest that both partner fidelity and conserved environmental filtering drive stable, stage-specific, social insect symbioses. We discuss the implications for our broader understanding of insect microbiomes, and the means of sustaining a beneficial microbiome.

The last Xerces blue butterfly was seen in the early 1940s, and its extinction is credited to human urban development. This butterfly has become a North American icon for insect conservation, but some have questioned whether it was truly a distinct species, or simply an isolated population of another living species. To address this question, we leveraged next-generation sequencing using a 93-year-old museum specimen. We applied a genome skimming strategy that aimed for the organellar genome and high-copy fractions of the nuclear genome by a shallow sequencing approach. From these data, we were able to recover over 200 million nucleotides, which assembled into several phylogenetically informative markers and the near-complete mitochondrial genome. From our phylogenetic analyses and haplotype network analysis we conclude that the Xerces blue butterfly was a distinct species driven to extinction.

BackgroundGut microbiomes can vary across development, a pattern often found for insects with complete metamorphosis. With varying nutritional need and distinct opportunities for microbial acquisition, questions arise as to how such ‘holometabolous’ insects retain helpful microbes at larval and adult stages. Ants are an intriguing system for such study. In a number of lineages adults digest only liquid food sources, while larvae digest solid foods. Like some other social insects, workers and soldiers of some ant species engage in oral-anal trophallaxes, enabling microbial transfer among siblings. But do queens, the typical colony founding caste, obtain symbionts through such transfer? Does this enable transgenerational symbiont passage? And does the resulting partner fidelity promote the evolution of beneficial symbionts? Furthermore, how might such adult-centric biology shape larval microbiomes? To address these questions, we characterized symbiotic gut bacteria across 13 species of Cephalotes turtle ants, with up to 40-million years of divergence. Adding to the prior focus on workers we, here, study underexplored castes and stages including queens, soldiers, and larvae, by performing 16S rRNA qPCR, amplicon sequencing, and phylogenetic classification.ResultsWe show that adult microbiomes are conserved across species and largely across castes. Nearly 95% of the bacteria in adults have, thus far, been found only in Cephalotes ants. Furthermore, the microbiomes from most adults exhibit phylosymbiosis, a trend in which microbiome community similarity recapitulates patterns of host relatedness. Additionally, an abundant, adult-enriched symbiont cospeciates with some Cephalotes. Evidence here suggests that these partner fidelity patterns extend from transgenerational symbiont transfer through alate gyne dispersal and subsequent colony-founding by queens. Like adults, larvae of Cephalotes species exhibit strong microbiome conservation. Phylosymbiosis patterns are weaker, however, with further evidence elevating environmental filtering as a primary mechanism behind such conservation. Specifically, while adult-enriched symbionts are found in most larvae, symbionts of older larvae are highly related to free-living bacteria from the Enterobacteriaceae, Lactobacillales, and Actinobacteria.ConclusionsOur findings suggest that both partner fidelity and conserved environmental filtering drive stable, stage-specific, social insect symbioses. We discuss the implications for our broader understanding of insect microbiomes, and the means of sustaining a beneficial microbiome.

Ants are an ecologically and evolutionarily diverse group, and they harbor a wide range of symbiotic microbial communities that often greatly affect their biology. Turtle ants (genus Cephalotes) engage in mutualistic relationships with gut bacteria and are exploited by microbial parasites. Studies have shown that associations among these microbial lineages and the turtle ant hosts vary geographically. However, these studies have been limited, and thorough within-species analyses of the variation and structure of these microbial communities have yet to be conducted. The giant turtle ant, Cephalotes atratus (Linnaeus 1758), is a geographically widespread, genetically diverse Neotropical species that has been sampled extensively across its geographic range, making it ideal for analysis of microbial associations. In this study, we verified the presence, genetic variation, and geographic patterns at the individual, colony, and population level of three microbial groups associated with the giant turtle ant: Wolbachia, a genus of facultative bacteria which are often parasitic, affecting host reproduction; Rhizobiales, a mutualistic order of bacteria hypothesized to be an obligate nutritional symbiont in turtle ants; and Ophiocordyceps, a genus of endoparasitic fungi infecting many arthropod species by manipulating their behavior for fungal reproduction. In this study, we found varying degrees of prevalence for two distantly related genotypes (haplogroups) of Wolbachia and high degree of prevalence of Rhizobiales across colonies with little genetic variation. In addition, we found low occurrence of Ophiocordyceps. This study highlights a key first step in understanding the diversity, distribution, and prevalence of the microbial community of C. atratus.

Symbiotic relationships between organisms are common throughout the tree of life, and often these organisms share an evolutionary history. In turtle ants (Cephalotes), symbiotic associations with bacteria are known to be especially important for supplementing the nutrients that their herbivorous diets do not provide. However, much remains unknown about the diversity of many common bacterial symbionts with turtle ants, such as Wolbachia. Here, we surveyed the diversity of Wolbachia, focusing on one species of turtle ant with a particularly wide geographic range, Cephalotes atratus. Colonies were collected from the entire range of C. atratus, and we detected the presence of Wolbachia by sequencing multiple individuals per colony for wsp. Then, using the multilocus sequence typing (MLST) approach, we determined each individual’s unique sequence type (ST) based on comparison to sequences published in the Wolbachia MLST Database ( https://pubmlst.org/wolbachia/ ). The results of this study suggest that there is a high level of diversity of Wolbachia strains among colonies from different regions, while the diversity within colonies is very low. Additionally, 13 novel variants (alleles) were uncovered. These results suggest that the level of diversity of Wolbachia within species is affected by geography, and the high level of diversity observed among Cephalotes atratus populations may be explained by their wide geographic range.

Huntsman spiders (Araneae: Sparassidae) are among the most speciose spider families, with a near-worldwide distribution, diverse habitats, equally diverse life histories, and five prolonged subsocial species. Previous molecular phylogenies have focused on individual subfamilies or clades. Here, we provide a phylogenetic inference with broadened sampling from 37 genera and eight of the eleven sparassid subfamilies. We increased taxon sampling by including species not previously sequenced and most available data on GenBank of two mitochondrial (COI, 16S rRNA) and two nuclear (H3, 28S rRNA) genes for a total of 262 ingroup taxa and nine outgroup taxa. Divergence dates were estimated using outgroup fossil taxa suggesting the sparassids evolved ∼ 100 mya (stem age), while the clade containing all subfamilies except Sparianthinae evolved ∼ 90 mya (stem age). Using a stochastic map approach with 40 species, this is the first sparassid phylogeny to incorporate extensive biology and life history data. Correlations of life history traits with solitary, subsocial, and prolonged subsocial behavior are examined using the D-test. Sparassid sociality is associated with life history traits that allow developing spiders to remain in their natal retreat longer (e.g., larger permanent retreats, plastered egg sacs, and ontogenetically delayed foraging), but is unrelated to body size or lifespan. Detailed morphological scoring of the endemic Australian subfamily Deleninae contextualizes existing molecular data, including in the Isopeda-Holconia-Isopedella complex. This study supports the monophyly of many major lineages, including for the first time, the Sparianthinae, but indicates multiple clades (Sparassinae and Eusparassinae) are paraphyletic and need further revision.

The last Xerces blue butterfly was seen in the early 1940s, and its extinction is credited to human urban development. This butterfly has become a North American icon for insect conservation, but some have questioned whether it was truly a distinct species, or simply an isolated population of another living species. To address this question, we leveraged next-generation sequencing using a 93-year-old museum specimen. We applied a genome skimming strategy that aimed for the organellar genome and high-copy fractions of the nuclear genome by a shallow sequencing approach. From these data, we were able to recover over 200 million nucleotides, which assembled into several phylogenetically informative markers and the near-complete mitochondrial genome. From our phylogenetic analyses and haplotype network analysis we conclude that the Xerces blue butterfly was a distinct species driven to extinction.

Gut compartments play an important role in structuring the microbial community within individual ants. The gut chambers of the turtle ant digestive tract differ remarkably in symbiont abundance and diversity., Microbial communities within the animal digestive tract often provide important functions for their hosts. The composition of eukaryotes’ gut bacteria can be shaped by host diet, vertical bacterial transmission, and physiological variation within the digestive tract. In several ant taxa, recent findings have demonstrated that nitrogen provisioning by symbiotic bacteria makes up for deficiencies in herbivorous diets. Using 16S rRNA amplicon sequencing and quantitative PCR, this study examined bacterial communities at a fine scale across one such animal group, the turtle ant genus Cephalotes. We analyzed the composition and colonization density across four portions of the digestive tract to understand how bacterial diversity is structured across gut compartments, potentially allowing for specific metabolic functions of benefit to the host. In addition, we aimed to understand if caste differentiation or host relatedness influences the gut bacterial communities of Cephalotes ants. Microbial communities were found to vary strongly across Cephalotes gut compartments in ways that transcend both caste and host phylogeny. Despite this, caste and host phylogeny still have detectable effects. We demonstrated microbial community divergence across gut compartments, possibly due to the various function of each gut compartment for digestion. IMPORTANCE Gut compartments play an important role in structuring the microbial community within individual ants. The gut chambers of the turtle ant digestive tract differ remarkably in symbiont abundance and diversity. Furthermore, caste type explains some variation in the microbiome composition. Finally, the evolutionary history of the Cephalotes species structures the microbiome in our study, which elucidates a trend in which related ants maintain related microbiomes, conceivably owing to cospeciation. Amazingly, gut compartment-specific signatures of microbial diversity, relative abundance, composition, and abundance have been conserved over Cephalotes evolutionary history, signifying that this symbiosis has been largely stable for over 50 million years.

Cephalotes are herbivorous ants (>115 species) feeding on low-nitrogen food sources, and they rely on gut symbionts to supplement their diet by recycling nitrogen food waste into amino acids. These conserved gut symbionts, which encompass five bacterial orders, have been studied previously for their primary nitrogen metabolism; however, little is known about their ability to biosynthesize specialized metabolites which can play a role in bacterial interactions between communities living in close proximity in the gut. To evaluate the biosynthetic potential of their gut symbionts, we mine 14 cultured isolate genomes and gut metagenomes across 17 Cephalotes species to explore the biodiversity of biosynthetic gene clusters (BGCs) producing specialized metabolites. The diversity of BGCs across Cephalotes phylogeny was analyzed using sequence similarity networking and BGC phylogenetic reconstruction. Our results reveal that the conserved gut symbionts involved in the nutritional symbiosis possess 80% of all the 233 BGCs retrieved in this work. Furthermore, the phylogenetic analysis of BGCs reveals different patterns of distribution, suggesting different mechanisms of conservation. A siderophore BGC shows high similarity in a single symbiont across different ant host species, whereas a BGC encoding the production of non-ribosomal peptides (NRPs) found different symbionts within a single host species. Additionally, BGCs were abundant in four of the five bacterial orders of conserved symbionts co-occurring in the hindgut. However, one major symbiont localized alone in the midgut lack BGCs. Because the spatial isolation prevents direct interaction with other symbionts, this result supports the idea that BGCs are maintained in bacteria living in close proximity but are dispensable for an alone-living symbiont. These findings together pave the way for studying the mechanisms of BGC conservation and evolution in gut bacterial genomes associated with Cephalotes. This work also provides a genetic background for further study, aiming to characterize bacterial specialized metabolites and to understand their functional role in multipartite mutualisms between conserved gut symbionts and Cephalotes turtle ants.

The most remarkable feature of our planet is the diversity of its life forms, ranging from viruses and nanobacteria to blue whales and giant sequoias to satanic leaf‐tailed geckos and leafy seadragons (look them up!). Life is found in essentially all environments on earth, and the number of species living on our planet is many times greater than we could have imagined a century ago. A well‐regarded estimate pegs the number of eukaryotic species on earth at 8.7 million (±1.3 million), of which fewer than 15% are currently described (Mora et al., 2011). The diversity of prokaryotes is less clear (and highly controversial), but an analysis of 1.6 billion 16S ribosomal RNA sequences estimated that 0.8–1.6 million prokaryotic operational taxonomic units exist globally (Louca et al., 2019). While we do not know how many species are currently extant, or have existed in the past, we do know that this biodiversity is valuable, providing food, fibre and medicine, furnishing ecosystem services such as water and air purification, nutrient cycling, pollination and carbon uptake, and contributing to technological innovations ranging from biotechnology to robotics to material science. Moreover, biodiversity underlies the cultural identity of human populations and is important to human health and well‐being. Geographically, species richness increases from the Polar Regions to the tropics in terrestrial and surface marine ecosystems. Thus, some countries, especially those in tropical and subtropical regions, are endowed with much greater biodiversity than others. Unfortunately, benefits arising from the access and utilization of this biodiversity have been unequally shared, with (paradoxically) biodiversity‐poor countries often accruing the lion's share of economic gains. There can be imbalances within countries as well, wherein some segments of the population obtain greater economic benefits from biodiversity and associated traditional knowledge than indigenous peoples. The “Nagoya Protocol on Access to Genetic Resources and the Fair and Equitable Sharing of Benefits Arising from their Utilization,” which came into force in 2014, is an international agreement designed to ensure that the benefits arising from biodiversity are shared equitably (https://www.cbd.int/abs/). However, few scientific journals require compliance with the Nagoya Protocol or the reporting of benefits from biodiversity research. In this editorial, we (the editors of Molecular Ecology and Molecular Ecology Resources) express support for the Nagoya Protocol and the principle of benefit sharing. We believe that scientific journals publishing research on biodiversity can play an important role in implementing the Nagoya Protocol and in reporting on benefits generated from such research. Below, we provide background on the Nagoya Protocol, discuss the kinds of benefits that may arise from biodiversity research, describe the rationale for reporting on these benefits and introduce changes to the journals’ Data Accessibility Statements to incorporate the requirements and goals of the Nagoya Protocol.

In insect-microbe nutritional symbioses the symbiont supplements the low nutrient diet of the host by producing amino acids and vitamins, and degrading lignin or polysaccharides. In multipartite mutualisms composed of multiple symbionts from different taxonomical orders, it has been suggested that in addition to the genes involved in the nutritional symbiosis the symbionts maintain genes responsible for the production of metabolites putatively playing a role in the maintenance and interaction of the bacterial communities living in close proximity. To test this hypothesis we investigated the diversity of biosynthetic gene clusters (BGCs) in the genomes and metagenomes of obligate gut symbionts associated with the herbivorous turtle ants (genus:Cephalotes). We studied 17Cephalotesspecies collected across several geographical areas to reveal that (i) mining bacterial metagenomes and genomes provides complementary results demonstrating the robustness of this approach with metagenomic data, (ii) symbiotic gut bacteria have a high diversity of BGCs which is correlated with host geography but not host phylogeny, (iii) the majority of the BGCs comes from the bacteria involved in the nutritional symbiosis supporting conserved metabolic functions for colonization, communication and competition in the gut environment, (iv) phylogenetic analysis of arylpolyene, polyketide (PK), and siderophore shows high similarity between BGCs of a single symbiont across different ant host species, while non-ribosomal peptide (NRP) shows high similarity between BGCs from different bacterial orders within a single host species suggesting multiple mechanisms for genome evolution of these obligate mutualistic gut bacteria.

Several studies have attempted to understand what may influence the bacterial community of a host, but studies examining whether different bacterial species are found in different parts of the body of insects are limited. In the present study, we address the following questions: 1) How are bacterial communities distributed across different parts of the body (head, mesosoma, gaster) of Camponotus and 2) Is the diversity found explained by the environment in which these ants were collected? Our results were able to differentiate the bacterial communities present in the different parts of the body and can be explained in the following way: each part of the body has unique organs with different functions; and the complex proventriculum of Camponotus may be acting as a filter and structuring the bacterial community found in the gaster. In addition, an unexpected finding of the present study was the high diversity found associated with the head and mesosoma, and our findings were able to confirm that this diversity is associated with the environment where the ants were collected. Knowing more about the factors that can influence bacterial communities may reveal more about the importance of these associations in nature.

International audience; To better understand the evolutionary significance of symbiotic interactions in nature, microbiome studies can help to identify the ecological factors that may shape host-associated microbial communities. In this study we explored both 16S and 18S rRNA microbial communities of D. armigerum from both wild caught individuals collected in the Amazon and individuals kept in the laboratory and fed on controlled diets. We also investigated the role of colony, sample type, development and caste on structuring microbial communities. Our bacterial results (16S rRNA) reveal that (1) there are colony level differences between bacterial communities; (2) castes do not structure communities; (3) immature stages (brood) have different bacterial communities than adults; and 4) individuals kept in the laboratory with a restricted diet showed no differences in their bacterial communities from their wild caught nest mates, which could indicate the presence of a stable and persistent resident bacterial community in this host species. The same categories were also tested for microbial eukaryote communities (18S rRNA), and (5) developmental stage has an influence on the diversity recovered; (6) the diversity of taxa recovered has shown this can be an important tool to understand additional aspects of host biology and species interactions. A prevailing question in studies of host-symbiont interactions is what are the host factors that affect their prokar-yotic and eukaryotic microbial communities. Microbial communities are influenced by features including geography, host phylogeny, diet and stages of development 1-7. However, no single factor consistently structures host-associated microbial communities across the tree of life. For example, in some ants diet explains substantial variation in gut microbial diversity 8-13. In contrast, for Pseudomyrmex ants a specialized plant-based diet was not as important as their relative trophic position for explaining microbial abundance and diversity 14. Understanding the patterns and exceptions affecting host-associated microbial diversity are critical to advancing our knowledge of these intimate relationships. One of the most common benefits provided by symbiosis is nutrition 15. Part of the evolutionary success of ants is attributed to food flexibility, which in some cases is directly linked to microbial symbionts 12,16,17. Several ant species have well-established bacterial communities and some provide essential nutrients to the ants. For example, members of the Camponotini tribe (Camponotus, Colobopsis and Polyrhachis) rely on endosymbiotic Blochmannia to obtain nitrogen 3,4,18-20 , and species in the genus Cephalotes rely on intestinal symbionts to recycle nitrogen for the host 10,12,21. However, the majority of ant taxa have not had their microbial communities studied, especially for eukaryotic microbes. In addition, understanding the factors that influence and modify the diversity of these associated microbes is important to understand their impact on the host.

Bacteria living on the cuticle of ants are generally studied for their protective role against pathogens, especially in the clade of fungus-growing ants. However, little is known regarding the diversity of cuticular bacteria in other ant host species, as well as the mechanisms leading to the composition of these communities. Here, we used 16S rRNA gene amplicon sequencing to study the influence of host species, species interactions and the pool of bacteria from the environment on the assembly of cuticular bacterial communities on two phylogenetically distant Amazonian ant species that frequently nest together inside the roots system of epiphytic plants, Camponotus femoratus and Crematogaster levior. Our results show that (a) the vast majority of the bacterial community on the cuticle is shared with the nest, suggesting that most bacteria on the cuticle are acquired through environmental acquisition, (b) 5.2% and 2.0% of operational taxonomic units (OTUs) are respectively specific to Ca. femoratus and Cr. levior, probably representing their respective core cuticular bacterial community, and (c) 3.6% of OTUs are shared between the two ant species. Additionally, mass spectrometry metabolomics analysis of metabolites on the cuticle of ants, which excludes the detection of cuticular hydrocarbons produced by the host, were conducted to evaluate correlations among bacterial OTUs and m/z ion mass. Although some positive and negative correlations are found, the cuticular chemical composition was weakly species-specific, suggesting that cuticular bacterial communities are prominently environmentally acquired. Overall, our results suggest the environment is the dominant source of bacteria found on the cuticle of ants.

Ant-plant interactions are diverse and abundant and include classic models in the study of mutualism and other biotic interactions. By estimating a time-scaled phylogeny of more than 1,700 ant species and a time-scaled phylogeny of more than 10,000 plant genera, we infer when and how interactions between ants and plants evolved and assess their macroevolutionary consequences. We estimate that ant-plant interactions originated in the Mesozoic, when predatory, ground-inhabiting ants first began foraging arboreally. This served as an evolutionary precursor to the use of plant-derived food sources, a dietary transition that likely preceded the evolution of extrafloral nectaries and elaiosomes. Transitions to a strict, plant-derived diet occurred in the Cenozoic, and optimal models of shifts between strict predation and herbivory include omnivory as an intermediate step. Arboreal nesting largely evolved from arboreally foraging lineages relying on a partially or entirely plant-based diet, and was initiated in the Mesozoic, preceding the evolution of domatia. Previous work has suggested enhanced diversification in plants with specialized ant-associated traits, but it appears that for ants, living and feeding on plants does not affect ant diversification. Together, the evidence suggests that ants and plants increasingly relied on one another and incrementally evolved more intricate associations with different macroevolutionary consequences as angiosperms increased their ecological dominance.

Andrew Edward Z. Short, Torsten Dikow, Corrie S. Moreau (2018): Entomological Collections in the Age of Big Data. Annual Review of Entomology 63: 513 - 530, DOI: 10.1146/annurev-ento-031616-035536 Abstract With a million described species and more than half a billion preserved specimens, the large scale of insect collections is unequaled by those of any other group. Advances in genomics, collection digitization, and imaging have begun to more fully harness the power that such large data stores can provide. These new approaches and technologies have transformed how entomological collections are managed and utilized. While genomic research has fundamentally changed the way many specimens are collected and curated, advances in technology have shown promise for extracting sequence data from the vast holdings already in museums. Efforts to mainstream specimen digitization have taken root and have accelerated traditional taxonomic studies as well as distribution modeling and global change research. Emerging imaging technologies such as microcomputed tomography and confocal laser scanning microscopy are changing how morphology can be investigated. This review provides an overview of how the realization of big data has transformed our field and what may lie in store. &nbsp

Made available in DSpace on 2018-12-11T17:11:10Z (GMT). No. of bitstreams: 0 Previous issue date: 2017-04-05 National Geographic Society Background: Symbiotic relationships between insects and bacteria are found across almost all insect orders, including Hymenoptera. However there are still many remaining questions about these associations including what factors drive host-associated bacterial composition. To better understand the evolutionary significance of this association in nature, further studies addressing a diversity of hosts across locations and evolutionary history are necessary. Ants of the genus Polyrhachis (spiny ants) are distributed across the Old World and exhibit generalist diets and habits. Using Next Generation Sequencing (NGS) and bioinformatics tools, this study explores the microbial community of >80 species of Polyrhachis distributed across the Old World and compares the microbiota of samples and related hosts across different biogeographic locations and in the context of their phylogenetic history. Results: The predominant bacteria across samples were Enterobacteriaceae (Blochmannia - with likely many new strains), followed by Wolbachia (with multiple strains), Lactobacillus, Thiotrichaceae, Acinetobacter, Nocardia, Sodalis, and others. We recovered some exclusive strains of Enterobacteriaceae as specific to some subgenera of Polyrhachis, corroborating the idea of coevolution between host and bacteria for this bacterial group. Our correlation results (partial mantel and mantel tests) found that host phylogeny can influence the overall bacterial community, but that geographic location had no effect. Conclusions: Our work is revealing important aspects of the biology of hosts in structuring the diversity and abundance of these host-associated bacterial communities including the role of host phylogeny and shared evolutionary history. Universidade Estadual Paulista Júlio de Mesquita Filho UNESP Campus Rio Claro Biologia, CEIS. Av. 24A, 1515, Bela Vista Field Museum of Natural History Department of Science and Education Integrative Research Center, 1400 South Lake Shore Drive Universidade Estadual Paulista Júlio de Mesquita Filho UNESP Campus Rio Claro Biologia, CEIS. Av. 24A, 1515, Bela Vista National Geographic Society: #9451-14