Dorymyrmex Mayr 1866, the ‘pyramid ants’ or ‘cone ants’, are conspicuous inhabitants of arid landscapes across the Americas. Ranging from the Great Plains to Patagonia, they are concentrated north and south of the tropics in contrast to the latitudinal diversity gradient canon. Despite being frequently collected and ecologically important, Dorymyrmex ants exemplify the taxonomic neglect typical in the subfamily Dolichoderinae.The genus has never had the benefit of a global revision, and even the major lineages are still uncertain. This work characterizes the issues at hand and ushers 22 Dorymyrmex species into the world of modern-day phylogenomics: By targeting ultraconserved elements (UCEs) across the genome, I construct an alignment of 1,891 loci, infer phylogenies under maximum likelihood and Bayesian approaches, and estimate divergence dates. Three major clades of Dorymyrmex emerge with maximal support, corresponding to former genera: Dorymyrmex sensu stricto, Araucomyrmex Gallardo 1919, and Conomyrma Forel 1913.The pyramicus group (‘Conomyrma’) shows a recent, rapid radiation with minimal morphological differentiation, reaffirming the difficulty of species delimitation in this widespread clade. Finally, I observe a general south-to-north pattern of dispersal, likely by way of savanna ‘stepping stones’ across the tropics during cooler, drier periods. Intercontinental dispersal occurred after the hypothetical Caribbean landspan in the Miocene, but before the Pleistocene or the completion of the Panamanian isthmus, suggesting dispersal by flight.This corroborates patterns observed in other arid-adapted amphitropical New World taxa. Characterizing the major Dorymyrmex species groups is an important first step towards stable taxonomic definitions—which underpin active studies in behavior, chemical ecology, and physiology.

Graphical Abstract

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.

Accurate identification and association of larval specimens with adults is a major challenge in insect taxonomy. Fortunately, it is now possible for nonexperts to sort collections of bulk samples with DNA barcodes rapidly and cost-effectively. We demonstrate this process using nanopore barcoding of 757 marine insects (Insecta: Gerromorpha), of which 81% were nymphs and many samples did not have co-occurring adult males for specific identification. We successfully associated 738 specimens (97%) to nine gerromorphan species, which would have been impossible to identify using morphological characters alone. This improved ability to incorporate information from all life-history stages has led to greater precision of species distributional ranges—knowledge that will be crucial for a more complete understanding of marine insects. We also highlighted two distinct, nonoverlapping Gerromorpha COI sequence databases on GenBank—a consequence of using two different primer sets to amplify different regions of COI. This issue inevitably hinders species identification with DNA-based methods, particularly for poorly represented groups such as marine insects. We bridged these databases by analyzing full-length COI sequences. We believe this will inspire future studies to incorporate DNA-based methods for more adult–larval association studies and for enhancing existing genetic resources, especially in understudied groups.

Using genetic, morphological, and geographical evidence, we investigate the species-level taxonomy and evolutionary history of the Pseudomyrmex elongatulus group, a clade of ants distributed from southwestern United States to Costa Rica. Through targeted enrichment of 2,524 UCE (ultraconserved element) loci we generate a phylogenomic data set and clarify the phylogenetic relationships and biogeographic history of these ants. The crown group is estimated to have originated ∼8 Ma, in Mexico and/or northern Central America, and subsequently expanded into southern Central America and the southwestern Nearctic.The P. elongatulus group contains a mix of low- and high-elevation species, and there were apparently multiple transitions between these habitat types. We uncover three examples of one species—of restricted or marginal geographical distribution—being embedded phylogenetically in another species, rendering the latter paraphyletic. One of these cases involves an apparent workerless social parasite that occurs sympatrically with its parent species, with the latter serving as host. This suggests a sympatric origin of the parasite species within the distribution range of its host. Species boundaries are tested using three molecular delimitation approaches (SODA, bPTP, BPP) but these methods generate inflated species estimates (26–46 species), evidently because of a failure to distinguish population structure from species differences. In a formal taxonomic revision of the P. elongatulus group, based on almost 3,000 specimens from ∼625 localities, we allow for geographic variation within species and we employ distinctness-in-sympatry criteria for testing hypotheses about species limits. Under these guidelines we recognize 13 species, of which nine are new: P. arcanus, sp. nov. (western Mexico); P. capillatus, sp. nov. (western Mexico); P. cognatus, sp. nov. (Chiapas, Mexico to Nicaragua); P. comitator, sp. nov. (Chiapas, Mexico); P. ereptor, sp. nov. (Veracruz, Mexico); P. exoratus, sp. nov. (southeastern Mexico, Honduras); P. fasciatus, sp. nov. (Chiapas, Mexico to Costa Rica); P. nimbus, sp. nov. (Costa Rica); and P. veracruzensis, sp. nov. (Veracruz, Mexico). Our study highlights the value of combining phylogenomic, phenotypic, and geographical data to resolve taxonomic and evolutionary questions.

Uncovering the evolutionary history of the subfamilies Ectatomminae and Heteroponerinae, or ectaheteromorphs, is key to understanding a major branch of the ant tree of life. Despite their diversity and ecological importance, phylogenetic relationships in the group have not been well explored. One particularly suitable tool for resolving phylogeny is the use of ultraconserved elements (UCEs), which have been shown to be ideal markers at a variety of evolutionary time scales. In the present study, we enriched and sequenced 2,127 UCEs from 135 specimens of ectaheteromorph ants and investigated phylogeny using a variety of model-based phylogenomic methods.Trees recovered from partitioned maximum-likelihood and species-tree analyses were well resolved and largely congruent.The results are consistent with an expanded concept of Ectatomminae that now includes the subfamily Heteroponerinae new synonym and its single tribe Heteroponerini new combination. Eleven monophyletic groups are recognized as genera: Acanthoponera, Alfaria status revived, Boltonia Camacho and Feitosa new genus, Ectatomma, Gnamptogenys, Heteroponera, Holcoponera status revived, Poneracantha status revived, Rhytidoponera, Stictoponera status revived, and Typhlomyrmex.The new phylogenetic framework and classification proposed here will shed light on the study of Ectatomminae taxonomy and systematics, as well as on the morphological evolution of the groups that it comprises.

The ant genus Nylanderia Emery has a cosmopolitan distribution and includes 150 extant described species and subspecies, with potentially hundreds more undescribed. Global taxonomic revision has long been stalled by strong intra- and interspecific morphological variation, limited numbers of diagnostic characters, and dependence on infrequently collected male specimens for species description and identification. Taxonomy is further complicated by Nylanderia being one of the most frequently intercepted ant genera at ports of entry worldwide, and at least 15 globetrotting species have widespread and expanding ranges, making species-level diagnoses difficult.Three species complexes (‘bourbonica complex’, ‘fulva complex’, and ‘guatemalensis complex’) include globetrotting species. To elucidate the phylogenetic positions of these three complexes and delimit species boundaries within each, we used target enrichment of ultraconserved elements (UCEs) from 165 specimens representing 98 Nylanderia morphospecies worldwide. We also phased the UCEs, effectively doubling sample size and increasing population-level sampling. After recovering strong support for the monophyly of each complex, we extracted COI barcodes and SNPs from the UCE data and tested within-complex morphospecies hypotheses using three molecular delimitation methods (SODA, bPTP, and STACEY). This comparison revealed that most methods tended to over-split taxa, but results from STACEY were most consistent with our morphospecies hypotheses. Using these results, we recommend species boundaries that are conservative and most congruent across all methods.This work emphasizes the importance of integrative taxonomy for invasive species management, as globetrotting occurs independently across at least nine different lineages across Nylanderia.

We here establish a new genus in the nymphalid butterfly subtribe Euptychiina, Cisandina Nakahara & Espeland, n. gen. to harbor five species hitherto placed within two polyphyletic genera, namely Magneuptychia Forster, 1964 and Euptychoides Forster, 1964. We compiled data from over 350 specimens in 17 public and private collections, as well as DNA sequence data for all relevant species, to revise the species-level classification of this new genus. According to our multi-locus molecular phylogeny estimated with the maximum likelihood approach, Cisandina lea n. comb., Cisandina philippa n. comb. & reinst. stat., Cisandina fida n. comb., Cisandina sanmarcos n. comb., and Cisandina trinitensis n. comb. are proposed as new taxonomic combinations, since these species are distantly related to the type species of Magneuptychia and Euptychoides and cannot reasonably be accommodated in any other genus. Lectotypes are designated for Papilio lea Cramer, 1777, Papilio junia Cramer, 1780, Euptychia philippa Butler, 1867, and Eupytchia fida Weymer, 1911. Two new species of Cisandina n. gen. are named and described herein, C. esmeralda Nakahara & Barbosa, n. sp. and C. castanya Lamas & Nakahara, n. sp., increasing the described species diversity of the genus to seven. The immature stages of C. castanya n. sp. and C. philippa n. comb. & reinst. stat. are documented along with their natural hostplants, representing the first two species of the genus with known life history information. We describe a new subspecies, Cisandina fida directa Nakahara & Willmott, n. ssp., based on a limited number of specimens from southern Ecuador and central Peru. We were unable to obtain genetic data for the nominate race of C. fida n. comb., and thus, this taxonomic hypothesis is currently based solely on phenotypic characters.

Se establece un nuevo género de mariposas ninfálidas de la subtribu Euptychiina, Cisandina Nakahara & Espeland, n. gen. para albergar cinco especies previamente ubicadas dentro de dos géneros polifiléticos, Magneuptychia Forster, 1964 y Euptychoides Forster, 1964. Se recopiló datos de más de 350 especímenes de 17 colecciones públicas y privadas, así como datos de secuencias de ADN para todas las especies relevantes y así poder revisar la clasificación a nivel de especie de este nuevo género. De acuerdo con nuestra filogenia molecular multilocus, estimada con el enfoque de máxima verosimilitud, se propone como nuevas combinaciones taxonómicas a Cisandina lea n. comb., Cisandina philippa n. comb. & reinst. stat., Cisandina fida n. comb., Cisandina sanmarcos n. comb. y Cisandina trinitensis n. comb., ya que estas especies se relacionan lejanamente con las especies tipo de Magneuptychia y Euptychoides y no pueden acomodarse razonablemente en ningún otro género. Se designa lectotipos para Papilio lea Cramer, 1777, Papilio junia Cramer, 1780, Euptychia philippa Butler, 1867 y, Eupytchia fida Weymer, 1911. Adicionalmente se nombra y describe aquí dos nuevas especies de Cisandina n. gen., C. esmeralda Nakahara & Barbosa, n. sp. y C. castanya Lamas & Nakahara, n. sp., aumentando la riqueza de especies descritas del género a siete. Los estadíos inmaduros de C. castanya Lamas & Nakahara, n. sp. y C. philippa n. comb. & reinst. stat., son documentados junto con su planta hospedante natural, aportando nueva información sobre el ciclo de vida del género. Además, describimos una nueva subespecie, Cisandina fida directa Nakahara & Willmott, n. ssp., con base en un número limitado de especímenes del sur de Ecuador y del centro de Perú. No obtuvimos datos genéticos para la raza nominada de C. fida n. comb., por lo que esta hipótesis taxonómica se establece únicamente con base en caracteres fenotípicos.

Estabelecemos aqui um novo gênero na subtribo de borboletas ninfalídeas Euptychiina, Cisandina Nakahara & Espeland, n. gen. para abrigar cinco espécies até agora alocadas dentro de dois gêneros polifiléticos, Magneuptychia Forster 1964 e Euptychoides Forster 1964. Compilamos dados de mais de 350 espécimes em 17 coleções públicas e privadas, bem como dados de sequência de DNA para todas as espécies relevantes, para revisar a classificação a nível de espécie deste novo gênero. De acordo com nossa filogenia molecular multilocus estimada com a abordagem de máxima verossimilhança, são propostas como novas combinações taxonômicas: Cisandina lea n. comb., Cisandina philippa n. comb. & reinst. stat., Cisandina fida n. comb., Cisandina sanmarcos n. comb. e Cisandina trinitensis n. comb., uma vez que essas espécies estão distantemente relacionadas às espécies-tipo de Magneuptychia e Euptychoides e não podem ser razoavelmente acomodadas em qualquer outro gênero. Lectótipos são designados para Papilio lea Cramer 1777, Papilio junia Cramer 1780, Euptychia philippa Butler 1867 e Eupytchia fida Weymer 1911. Duas novas espécies de Cisandina n. gen. são nomeadas e descritas aqui, C. esmeralda Nakahara & Barbosa, n. sp. e C. castanya Lamas & Nakahara, n. sp., resultando no aumento da diversidade de espécies do gênero para sete. Os estágios imaturos de C. castanya n. sp. e C. philippa n. comb. & reinst. stat., são documentados junto com sua planta hospedeira natural, representando duas espécies com informações de história de vida conhecidas para o gênero. Descrevemos uma nova subespécie, Cisandina fida directa Nakahara & Willmott, n. ssp., com base em um número limitado de espécimes do sul do Equador e centro do Peru. Não foi possível obter dados genéticos para a raça nominal de C. fida n. comb., e, portanto, esta hipótese taxonômica é atualmente baseada apenas em caracteres fenotípicos.

The evolutionary history of fungus-farming ants has been the subject of multiple morphological, molecular phylogenetic, and phylogenomic studies. Due to its rarity, however, the phylogenetic position, natural history, and fungal associations of the monotypic genus Paramycetophylax Kusnezov have remained enigmatic. Here we report the first excavations of colonies of Paramycetophylax bruchi (Santschi) and describe its nest architecture and natural history. Utilizing specimens from these collections, we generated ultraconserved-element (UCE) data to determine the evolutionary position of Paramycetophylax within the fungus-farming ants and ribosomal ‘fungal barcoding’ ITS sequence data to identify the fungal cultivar. A maximum-likelihood phylogenomic analysis indicates that the genus Paramycetophylax is the sister group of the yeast-cultivating Cyphomyrmex rimosus group, an unexpected result that renders the genus Cyphomyrmex Mayr paraphyletic. A Bayesian divergence-dating analysis indicates that Paramycetophylax diverged from its sister group around 36 mya (30–42 mya, HPD) in the late Eocene-early Oligocene, a period of global cooling, expansion of grasslands, and large-scale extinction of tropical organisms. Bayesian analysis of the fungal cultivar ITS gene fragment indicates that P. bruchi practices lower agriculture and that the cultivar grown by P. bruchi belongs to the Clade 1 group of lower-attine fungi, a clade that, interestingly, also includes the C. rimosus-group yeast cultivars. Based on these results, we conclude that a better understanding of P. bruchi and its fungal cultivar, including whole-genome data, is critical for reconstructing the origin of yeast agriculture, a major transition in the evolution of fungus-farming ants.