Mitogenome architecture supports the non-monophyly of the cosmopolitan parasitoid wasp subfamily Doryctinae (Hymenoptera: Braconidae) recovered by nuclear and mitochondrial phylogenomics.

Mitochondrial DNA gene organisation is an important source of phylogenetic information for various metazoan taxa at different evolutionary timescales, though this has not been broadly tested for all insect groups nor within a phylogenetic context. The cosmopolitan subfamily Doryctinae is a highly diverse group of braconid wasps mainly represented by ectoparasitoids of xylophagous beetle larvae. Previous molecular studies based on Sanger and genome-wide (ultraconserved elements, UCE; and mitochondrial genomes) sequence data have recovered a non-monophyletic Doryctinae, though the relationships involved have always been weakly supported. We characterised doryctine mitogenomes and conducted separate phylogenetic analyses based on mitogenome and UCE sequence data of ~100 representative doryctine genera to assess the monophyly and higher-level classification of the subfamily. We identified rearrangements of mitochondrial transfer RNAs (tRNAs) that support a non-monophyletic Doryctinae consisting of two separate non-related clades with strong geographic structure ('New World' and 'Old World' clades). This geographic structure was also consistently supported by the phylogenetic analyses preformed with mitogenome and UCE sequence data. These results highlight the utility of the mitogenome gene rearrangements as a potential source of phylogenetic information at different evolutionary timescales.

Multiple introgression events during the diversification history of the edible Mexican grasshopper genus Sphenarium (Orthoptera: Pyrgomorphidae).

Speciation with gene flow often leads to ambiguous phylogenetic reconstructions, reticulate patterns of relatedness and conflicting nuclear versus mitochondrial (mt) lineages. Here we employed a fragment of the COI mtDNA gene and nuclear genome-wide data (3RAD) to assess the diversification history of Sphenarium, an orthopteran genus of great economic importance in Mexico that is presumed to have experienced hybridisation events in some of its species. We carried out separate phylogenetic analyses to evaluate the existence of mito-nuclear discordance in the species relationships, and also assessed the genomic diversity and population genomic structure and investigated the existence of interspecific introgression and species limits of the taxa involved based on the nuclear dataset. The species delineation analyses discriminated all the currently recognised species, but also supported the existence of four undescribed species. The mt and nuclear topologies had four discordant species relationships that can be explained by mt introgression, where the mt haplotypes of S. purpurascens appear to have replaced those of S. purpurascens A and B, S. variabile and S. zapotecum. Moreover, our analyses supported the existence of nuclear introgression events between four species pairs that are distributed in the Sierra Madre del Sur province in southeast Mexico, with three of them occurring in the Tehuantepec Isthmus region. Our study highlights the relevance of genomic data to address the relative importance of allopatric isolation versus gene flow in speciation.

Mitochondrial phylogenomics and mitogenome organization in the parasitoid wasp family Braconidae (Hymenoptera: Ichneumonoidea).

BACKGROUND: Mitochondrial (mt) nucleotide sequence data has been by far the most common tool employed to investigate evolutionary relationships. While often considered to be more useful for shallow evolutionary scales, mt genomes have been increasingly shown also to contain valuable phylogenetic information about deep relationships. Further, mt genome organization provides another important source of phylogenetic information and gene reorganizations which are known to be relatively frequent within the insect order Hymenoptera. Here we used a dense taxon sampling comprising 148 mt genomes (132 newly generated) collectively representing members of most of the currently recognised subfamilies of the parasitoid wasp family Braconidae, which is one of the largest radiations of hymenopterans. We employed this data to investigate the evolutionary relationships within the family and to assess the phylogenetic informativeness of previously known and newly discovered mt gene rearrangements. RESULTS: Most subfamilial relationships and their composition obtained were similar to those recovered in a previous phylogenomic study, such as the restoration of Trachypetinae and the recognition of Apozyginae and Proteropinae as valid braconid subfamilies. We confirmed and detected phylogenetic signal in previously known as well as novel mt gene rearrangements, including mt rearrangements within the cyclostome subfamilies Doryctinae and Rogadinae. CONCLUSIONS: Our results showed that both the mt genome DNA sequence data and gene organization contain valuable phylogenetic signal to elucidate the evolution within Braconidae at different taxonomic levels. This study serves as a basis for further investigation of mt gene rearrangements at different taxonomic scales within the family.

Phylogenomics of braconid wasps (Hymenoptera, Braconidae) sheds light on classification and the evolution of parasitoid life history traits.

The parasitoid lifestyle is largely regarded as a key innovation that contributed to the evolutionary success and extreme species richness of the order Hymenoptera. Understanding the phylogenetic history of hyperdiverse parasitoid groups is a fundamental step in elucidating the evolution of biological traits linked to parasitoidism. We used a genomic-scale dataset based on ultra-conserved elements and the most comprehensive taxon sampling to date to estimate the evolutionary relationships of Braconidae, the second largest family of Hymenoptera. Based on our results, we propose Braconidae to comprise 41 extant subfamilies, confirmed a number of subfamilial placements and proposed subfamily-level taxonomic changes, notably the restoration of Trachypetinae stat. rev. and Masoninae stat. rev. as subfamilies of Braconidae, confirmation that Apozyx penyai Mason belongs in Braconidae placed in the subfamily Apozyginae and the recognition of Ichneutinae sensu stricto and Proteropinae as non-cyclostome subfamilies robustly supported in a phylogenetic context. The correlation between koinobiosis with endoparasitoidism and idiobiosis with ectoparasitoidism, long thought to be an important aspect in parasitoid life history, was formally tested and confirmed in a phylogenetic framework. Using ancestral reconstruction methods based on both parsimony and maximum likelihood, we suggest that the ancestor of the braconoid complex was a koinobiont endoparasitoid, as was that of the cyclostome sensu lato clade. Our results also provide strong evidence for one transition from endo- to ectoparasitoidism and three reversals back to endoparasitoidism within the cyclostome sensu stricto lineage. Transitions of koino- and idiobiosis were identical to those inferred for endo- versus ectoparasitoidism, except with one additional reversal back to koinobiosis in the small subfamily Rhysipolinae.

Genome and cuticular hydrocarbon-based species delimitation shed light on potential drivers of speciation in a Neotropical ant species complex.

Geographic separation that leads to the evolution of reproductive isolation between populations generally is considered the most common form of speciation. However, speciation may also occur in the absence of geographic barriers due to phenotypic and genotypic factors such as chemical cue divergence, mating signal divergence, and mitonuclear conflict. Here, we performed an integrative study based on two genome-wide techniques (3RAD and ultraconserved elements) coupled with cuticular hydrocarbon (CHC) and mitochondrial (mt) DNA sequence data, to assess the species limits within the Ectatomma ruidum species complex, a widespread and conspicuous group of Neotropical ants for which heteroplasmy (i.e., presence of multiple mtDNA variants in an individual) has been recently discovered in some populations from southeast Mexico. Our analyses indicate the existence of at least five distinct species in this complex: two widely distributed across the Neotropics, and three that are restricted to southeast Mexico and that apparently have high levels of heteroplasmy. We found that species boundaries in the complex did not coincide with geographic barriers. We therefore consider possible roles of alternative drivers that may have promoted the observed patterns of speciation, including mitonuclear incompatibility, CHC differentiation, and colony structure. Our study highlights the importance of simultaneously assessing different sources of evidence to disentangle the species limits of taxa with complicated evolutionary histories.

Ultraconserved elements-based systematics reveals evolutionary patterns of host-plant family shifts and phytophagy within the predominantly parasitoid braconid wasp subfamily Doryctinae.

Phytophagy has promoted species diversification in many insect groups, including Hymenoptera, one of the most diverse animal orders on Earth. In the predominantly parasitoid family Braconidae, an association with insect-induced, plant galls in angiosperms have been reported in three subfamilies, but in particular in the Doryctinae, where it has been recorded to occur in species of ten genera. Allorhogas Gahan is the most species-rich of these genera, with its species having different phytophagous strategies. Here we conducted a comprehensive phylogenomic study for the doryctine gall-associated genera, with an emphasis on Allorhogas, using ultraconserved elements (UCEs). Based on this estimate of phylogeny we: (1) evaluated their taxonomic composition, (2) estimated the timing of origin of the gall-associated clade and divergence of its main subclades, and (3) performed ancestral state reconstruction analyses for life history traits related to their host-plant association. Our phylogenetic hypothesis confirmed Allorhogas as polyphyletic, with most of its members being nested in a main clade composed of various subclades, each comprising species with a particular host-plant family and herbivorous feeding habit. The origin of gall-association was estimated to have occurred during the late Oligocene to early Miocene, with a subsequent diversification of subclades during the middle to late Miocene and Pliocene. Overlap in divergence timing appears to occur between some taxa and their host-associated plant lineages. Evolution of the feeding strategies in the group shows "inquilinism-feeding" as the likely ancestral state, with gall-formation in different plant organs and seed predation having independently evolved on multiple occasions.

Midgut transcriptome assessment of the cockroach-hunting wasp Ampulex compressa (Apoidea: Ampulicidae).

The emerald jewel wasp Ampulex compressa (Hymenoptera: Ampulicidae) is a solitary wasp that is widely known for its specialized hunting of cockroaches as larvae provision. Adult wasps mainly feed on pollen and nectar, while their larvae feed on the cockroachs' body, first as ecto- and later as endoparsitoids. Little is known about the expression of digestive, detoxification and stress-response-related genes in the midgut of A. compressa, or about its transcriptional versatility between life stages. To identify gut-biased genes related to digestion, detoxification, and stress response, we explored the midgut transcriptome of lab-reared A. compressa, for both adults and larvae, by focusing on the top 100 significantly up- and down-regulated genes. From the top 100 significantly differentially expressed genes (DEGs), we identified 39 and 36 DEGs putatively related to digestion and detoxification in the adult wasps and larvae, respectively. The two carbohydrases alpha-glucosidase (containing an alpha-amylase domain) and glycosyl hydrolase family 31, as well as the two proteinases chymotrypsin and trypsin, revealed the highest gene diversity. We identified six significant DEGs related to detoxification, which comprise glutathione S-transferase, cytochrome P450s and UDP-glucuronosyltransferase. The gene expression levels that were significantly expressed in both life stages vary strongly between life stages, as found in genes encoding for chymotrypsin and trypsin or glycosyl hydrolases family 31. The number of genes related to alpha-glucosidase, glycosyl hydrolase family 31, and cytochrome P450s was found to be similar across nine reference hymenopteran species, except for the identified glycosyl hydrolase family 31 gene, which was absent in all reference bee species. Phylogenetic analyses of the latter candidate genes revealed that they cluster together with their homologous genes found in the reference hymenopteran species. These identified candidate genes provide a basis for future comparative genomic and proteomic studies on (ontogenetic) dietary transitions in Hymenoptera.

Revision of Palaearctic Idiotypa (Hymenoptera, Diapriidae, Diapriinae, Spilomicrini).

A revision of the Palaearctic species of the genus Idiotypa Förster is provided. The genus Eunuchopria Szabó, 1961 is a junior synonym of Idiotypa Förster, 1856 syn. n. and the new combination Idiotypa nitens (Szabó, 1961) comb. n., is established. Dublicate original spellings I. marii and I. mariae are resolved by first reviser action; I. mariae is now the correct original spelling. Lectotypes are designated for Idiotypa mariae and I. maritima. New synonymy is proposed: I. maritima (Haliday, 1833) = I. rufiventris (Thomson, 1858) syn. n.; = I. nigriceps Kieffer, 1909 syn. n.; = I. nigriceps Kieffer, 1911 syn. n. The three valid species I. mariae Gregor, 1939, I. maritima (Haliday, 1833) and I. nitens (Szabó, 1961) are redescribed, illustrated and keyed.

Observed Ecological Communities Are Formed by Species Combinations That Are among the Most Likely to Persist under Changing Environments.

AbstractDespite the rich biodiversity found in nature, it is unclear to what extent some combinations of interacting species, while conceivable in a given place and time, may never be realized. Yet solving this problem is important for understanding the role of randomness and predictability in the assembly of ecological communities. Here we show that the specific combinations of interacting species that emerge from the ecological dynamics within regional species pools are not all equally likely to be seen; rather, they are among the most likely to persist under changing environments. First, we use niche-based competition matrices and Lotka-Volterra models to demonstrate that realized combinations of interacting species are more likely to persist under random parameter perturbations than the majority of potential combinations with the same number of species that could have been formed from the regional pool. We then corroborate our theoretical results using a 10-year observational study, recording 88 plant-herbivore communities across three different forest successional stages. By inferring and validating plant-mediated communities of competing herbivore species, we find that observed combinations of herbivores have an expected probability of species persistence higher than half of all potential combinations. Our findings open up the opportunity to establish a formal probabilistic and predictive understanding of the composition of ecological communities.

Phylogenomics of the Mesoamerican alligator-lizard genera Abronia and Mesaspis (Anguidae: Gerrhonotinae) reveals multiple independent clades of arboreal and terrestrial species.

Abronia and Mesaspis are two of the five anguid lizard genera in the subfamily Gerrhonotinae. Their members are restricted to Mesoamerica, and most have allopatric distributions. Species of Abronia are primarily arboreal and occur in cloud and seasonally dry pine-oak forests, whereas those of Mesaspis are terrestrial and inhabit mesic microhabitats of montane forests. Recent molecular studies suggest that although these genera together form a monophyletic group, neither genus is monophyletic. Here we performed a phylogenetic study of Abronia and Mesaspis based on the most comprehensive taxonomic sampling of these genera to date and double digest restriction site-associated (ddRADseq) data. Our reconstructed phylogeny differed considerably from all previously published topologies, consistently recovering multiple independent clades of arboreal and terrestrial species and Abronia and Mesaspis as non-monophyletic. Geography, rather than current taxonomy, provides the best explanation of their phylogenetic relationships. Our analyses consistently recovered two main clades, distributed on the highlands of Middle America east and west of the Isthmus of Tehuantepec, respectively, and each composed of subclades of Abronia and Mesaspis. In the former main clade, members of the subgenus Auriculabronia formed the sister taxon to the Mesaspis moreletii complex, whereas the main clade west of the Isthmus was composed of two clades with a subclade of Abronia and another of Mesaspis each (one clade on the Atlantic versant of the main mountain ranges of eastern Mexico and another one on the Sierra Madre del Sur exclusive of its Atlantic versant) and a third clade with species of the subgenera Abronia and Scopaeabronia. We discuss the taxonomic implications of our results for the classification of the examined taxa and list the morphological characters that diagnose the recovered clades. This study highlights the utility of ddRADseq data to reconstruct the evolutionary history of supraspecific vertebrate taxa.

Information arms race explains plant-herbivore chemical communication in ecological communities.

Plants emit an extraordinary diversity of chemicals that provide information about their identity and mediate their interactions with insects. However, most studies of this have focused on a few model species in controlled environments, limiting our capacity to understand plant-insect chemical communication in ecological communities. Here, by integrating information theory with ecological and evolutionary theories, we show that a stable information structure of plant volatile organic compounds (VOCs) can emerge from a conflicting information process between plants and herbivores. We corroborate this information "arms race" theory with field data recording plant-VOC associations and plant-herbivore interactions in a tropical dry forest. We reveal that plant VOC redundancy and herbivore specialization can be explained by a conflicting information transfer. Information-based communication approaches can increase our understanding of species interactions across trophic levels.

Phylogeny of the North-Central American clade of blood-sucking reduviid bugs of the tribe Triatomini (Hemiptera: Triatominae) based on the mitochondrial genome.

Triatominae is a subfamily of blood-sucking reduviid hemipterans of public health importance primarily in tropical and sub-tropical regions of the Americas, whose members possess various morphological adaptations closely associated to hematophagy. Despite their medical importance, the systematics of the subfamily is far from resolved, particularly within the tribe Triatomini. Here we employed mitochondrial genome DNA sequences to reconstruct the phylogenetic relationships among 19 species of the North-Central American (NCA) clade of Triatomini and to estimate the times of origin and diversification of its main clades. Twenty-nine mitogenomes were examined for representative specimens of 25 species, including the outgroup. Phylogenetic informativeness estimated for each protein-coding gene showed that cox1, cox2 and atp6 were the most informative markers, whereas atp8 and nad4 had high saturation levels. Phylogenetic analyses excluding the latter two protein-coding genes recovered an almost fully resolved topology. The NCA clade apparently originated shortly after emergence of an initial land bridge of the Panama Isthmus, ca. 15.05-20.05 Mya. An Asian/pantropical subclade with Linshcosteus costalis, Triatoma rubrofasciata and T. migrans was nested within the NCA clade, from which it diverged ca. 12.42-17.3Mya. Uncorrected cox1 and 13 protein-coding gene distances suggest the existence of additional species within the dimidiata complex. In contrast, T. phyllosoma, T. mazzottii and T. longipennis, from the phyllosoma complex, have considerably low cox1 and 13 PCG distances among them, suggesting mitochondrial introgression or conspecificity. Our study yielded a robust phylogeny for the group, which could be tested with further phylogenetic hypotheses based on nuclear genome-wide markers.

New species of the genus Caloxiphus Saussure amp; Pictet, 1898 (Orthoptera: Tettigoniidae) from the Huasteca Region, Hidalgo, Mexico.

Two new species of the genus Caloxiphus Saussure Pictet, 1898 (Pseudophyllinae) are described: C. chapulhuacan n. sp., and C. cuicani n. sp., both endemic to the Huasteca Region, State of Hidalgo, Mexico. These two new taxa show morphological affinities to C. championi Saussure Pictet, 1898. However, they may be separated from the latter species on basis of external and internal (genitalia) morphological characters that are provided and illustrated. Acoustic signals for C. cuicani n. sp., and information on distribution for both new taxa are given.

Morphological variation of the widely distributed genus Stenocorse Marsh, 1968 (Hymenoptera: Braconidae: Doryctinae).

Stenocorse is a monotypic genus with wide distribution and a large range of beetle hosts. We analyzed the morphological variation of 346 specimens from the USA south to Brasil. We studied 15 morphometric and 30 discrete characters using principal component (PCA) and discriminant function analyses (DFA) to assess character informativeness and the influence of geographic distribution and host source to detect differentiation. Mexican samples were studied according to location and biogeographic provinces. Specimens from Colombia were studied according to the plant where the host was recorded. Three measurements show group differentiation whereas four were redundant. Three groups of individuals were supported by continuous and discrete characters: one found in the USA, Mexico, Nicaragua and Costa Rica, a second from Mexico, and a third from Colombia and Brazil. These groups showed poor agreement with the differentiation of its common beetle host populations. This could be a consequence of the large number of sympatric host species feeding on a large number of plant species. This research shed light on other sources of evidence for building a sound taxonomy for Stenocorse.

Molecular systematics of the Dichopetala genus group (Orthoptera: Phaneropteridae)

Introducción: El grupo de géneros Dichopetala se propuso recientemente después de una revisión del género Dichopetala Brunner von Wattenwyl, 1878. Actualmente, el grupo consta de ocho géneros y 44 especies distribuidas desde el sur de los Estados Unidos hasta el sur de México. Este acuerdo genérico, se basó únicamente en evidencia morfológica y se acompañó por discusiones sobre nuevos géneros erigidos, para los cuales no se probó su monofilia. Objetivo: Evaluar las relaciones filogenéticas entre especies representativas de los ocho géneros del grupo Dichopetala. Métodos: Generamos secuencias de ADN para un gen mitocondrial (Citocromo oxidasa I: COI) y dos marcadores de genes nucleares (28S, Histona III: H3), e incluimos especies de otros géneros de Phaneropterinae para probar la monofilia del grupo en estudio. Utilizamos modelos evolutivos bayesianos y de máxima verosimilitud. Resultados: Se respalda la monofilia del grupo Dichopetala y la monofilia de los géneros Dichopetala, Obolopteryx, Planipollex, Mactruchus y Rhabdocerca. Además, los géneros Acanthorintes y Pterodichopetala como parafiléticos. Los marcadores mitocondriales también sugieren que los géneros Rhabdocerca y Acanthorintes ampliamente distribuidos, pueden en realidad contener varias especies no vistas previamente. Conclusión: Se proporciona la primera contribución a la filogenia del grupo de Dichopetala y una definición filogenética y morfológica más robusta de algunos de los géneros involucrados.

Introduction: The Dichopetala genus group was proposed recently after revision of the genus Dichopetala Brunner von Wattenwyl, 1878. Currently, the group consists of eight genera and 44 species distributed from Southern United States to Southern Mexico. This generic arrangement was based solely on morphological evidence, and was accompanied by discussions on new erected genera, for which their monophyly was not tested. Objective: To assess the phylogenetic relationships among representative species of the eight genera of the Dichopetala group. Methods: We generated DNA sequences for one mitochondrial (Cytochrome oxidase I: COI) and two nuclear (28S, Histone III: H3) gene markers, and included species of other Phaneropterinae genera to test the monophyly of the ingroup; Bayesian and maximum likelihood evolutionary models were used. Results: The monophyly of the Dichopetala group and the monophyly of genera Dichopetala, Obolopteryx, Planipollex, Mactruchus and Rhabdocerca is supported. In addition, Acanthorintes and Pterodichopetala were recovered as paraphyletic. The mitochondrial markers also suggest that the widely distributed genera Rhabdocerca and Acanthorintes may actually contain various overlooked species. Conclusions: The first contribution on the Phylogeny of the Dichopetala group, and a more robust phylogenetic and morphological definition of some of the genera involved are provided.

A new aberrant Doryctinae genus (Hymenoptera: Braconidae) from French Guiana.

A new genus, Cerritulus gen. nov., with type species, C. forticrura sp. nov., are described from French Guiana based on a single specimen that is considerably distinct morphologically from all known Neotropical genera. The new genus is only partially similar to the enigmatic, monotypic Asian genera Ceylonspathius Belokobylskij and Termitospathius Beloko-bylskij, whose species were collected inside termite nests. We provide colour pictures for the type species of the above three genera.

Restriction-site associated DNA markers provide new insights into the evolutionary history of the bark beetle genus Dendroctonus.

The bark beetle genus Dendroctonus contains some of the most economically important pests of conifers worldwide. Despite many attempts, there is no agreement today on the phylogenetic relationships within the genus, which limits our understanding of its evolutionary history. Here, using restriction-site associated DNA (RAD) markers from 70 specimens representing 17 species (85% of the known diversity) we inferred the phylogeny of the genus, its time of origin and biogeographic history, as well as the evolution of key ecological traits (host plants, larval behavior and adults' attack strategies). For all combinations of tested parameters (from 6444 to 23,570 RAD tags analyzed), the same, fully resolved topology was inferred. Our analyses suggest that the most recent common ancestor (mrca) of all extant Dendroctonus species was widely distributed across eastern Palearctic and western Nearctic during the early Miocene, from where species dispersed to other Holarctic regions. A first main inter-continental vicariance event occurred during early Miocene isolating the ancestors of D. armandi in the Palearctic, which was followed by the radiation of the main Dendroctonus lineages in North America. During the Late Miocene, the ancestor of the 'rufipennis' species group colonized north-east Palearctic regions from western North America, which was followed by a second main inter-continental vicariance event isolating Pleistocene populations in Asia (D. micans) and western North America (D. murrayanae and D. punctatus). The present study supports previous hypotheses explaining intercontinental range disjunctions across the Northern Hemisphere by the fragmentation of a continuous distribution due to climatic cooling, host range fragmentation and geological changes during the late Cenozoic. The reconstruction of ancestral ecological traits indicates that the mrca bored individual galleries and mass attacked the boles of pines. The gregarious feeding behavior of the larvae as well as the individual attack of the base of trees have apparently independently evolved twice in North America (in the 'rufipennis' and the 'valens' species groups), which suggests a higher adaptive potential than previously thought and may be of interest for plant protection and biodiversity conservation in a rapidly changing world.

3RAD-based systematics of the transitional Nearctic-Neotropical lubber grasshopper genus Taeniopoda (Orthoptera: Romaleidae).

The genus Taeniopoda Stål (Romaleidae) is a group of Nearctic-Neotropical grasshoppers whose systematics has been largely neglected. A recent phylogenetic study based on morphology and mitochondrial and nuclear markers failed to resolve the species boundaries in this genus and showed a lack of reciprocal exclusivity between T. eques (Burmeister) and T. tamaulipensis Rehn. Here we assessed the species limits and phylogenetic relationships in Taeniopoda based on 3RAD data, and evaluated the presence of gene flow and niche overlap between the above two species using clustering and ecological niche modelling (ENM) analyses to determine their taxonomic status. We performed de novo assembly of different 3RAD data sets with distinct parameters settings to explore whether they impact the recovered relationships. Ten species were consistently delimited, with T. picticornis and T. stali regarded as conspecific and the populations of T. auricornis from Guatemala representing a separate species. We maintained the specific status of T. eques and T. tamaulipensis, though our results suggest that they represent a ring species since their genetic composition appear to change gradually following a "loop form" along their geographical distribution. The phylogenomic analyses confirmed the paraphyly of Taeniopoda with respect to Romalea and recovered three major clades. Similar to previous studies, the relationships of our examined matrices were highly congruent despite their different levels of missing data. However, the similarity threshold and minimum number of samples that must share a locus for it to be retained impact the amount of loci and missing data of the matrices. This study demonstrates the utility of 3RAD to detect gene flow and to resolve species limits and phylogenetic relationships among closely related taxa.

Ontogenic synchronization of Bephratelloides cubensis, Annona macroprophyllata seeds and acetogenins from Annonaceae.

The seeds of Annona macroprophyllata Donn. Sm. contain idioblasts with toxic acetogenins, including laherradurin and rolliniastatin-2, in relatively high proportions. Both metabolites are cataloged as potent insecticides for several species, even so, the wasp Bephratelloides cubensis Ashmead fulfills almost its entire life cycle inside the seeds of this and other annonaceous species, to such a degree, that they constitute a strong selection pressure. In order to document the chemical relationship between the two species, it is reported for the first time in this paper the presence of idioblasts and acetogenins during the ontogenic development of the seeds of A. macroprophyllata, and contrasted with the development of B. cubensis. The results indicate that idioblasts with laherradurin and rolliniastatin-2 acetogenins are formed in the middle stages of the endospermic development, also that both acetogenins are biosynthesized simultaneously, and that their proportion is dependent on the degree of development. The acetogenins are present in high amounts that suppose a sufficient toxic barrier and, in this case, laherradurin is the most abundant (> 1000 µg g dry weight-1). The wasp B. cubensis only emerges from the seeds to copulate and returns for oviposition; its larval phase coincides with the appearance of acetogenins, so it feeds on the acetogenic endosperm. The absence of acetogenins in the tissues and excreta of the insect supposes a metabolization of the molecules, which would explain the tolerance to its toxicity.

High extinction rates and non-adaptive radiation explains patterns of low diversity and extreme morphological disparity in North American blister beetles (Coleoptera, Meloidae).

Untangling the relationship between morphological evolution and lineage diversification is key to explain global patterns of phenotypic disparity across the Tree of Life. Few studies have examined the relationship between high morphological disparity and extinction. In this study, we infer phylogenetic relationships and lineage divergence times within Eupomphini (Meloidae), a tribe of blister beetles endemic to the arid zone of North America, which exhibits a puzzling pattern of very low species richness but wild variation in morphological diversity across extant taxa. Using Bayesian and maximum likelihood inference, we estimate diversification and phenotypic evolutionary rates and infer the time and magnitude of extinction rate shifts and mass extinction events. Our results suggest that Eupomphini underwent an event of ancient radiation coupled with rapid morphological change, possibly linked to the loss of the evolutionary constraint in the elytral shape. A high extinction background associated to the Miocene-Pliocene transition decimated the diversity within each major clade, resulting in the species-poor genera observed today. Our study supports a connection between high extinction rates and patterns of decoupled phenotypic evolution and lineage diversification, and the possibility of a radiation in the absence of ecological release.