Chromosome-Aware Phylogenomics of Assassin Bugs (Hemiptera: Reduvioidea) Elucidates Ancient Gene Conflict.

Though the phylogenetic signal of loci on sex chromosomes can differ from those on autosomes, chromosomal-level genome assemblies for nonvertebrates are still relatively scarce and conservation of chromosomal gene content across deep phylogenetic scales has therefore remained largely unexplored. We here assemble a uniquely large and diverse set of samples (17 anchored hybrid enrichment, 24 RNA-seq, and 70 whole-genome sequencing samples of variable depth) for the medically important assassin bugs (Reduvioidea). We assess the performance of genes based on multiple features (e.g., nucleotide vs. amino acid, nuclear vs. mitochondrial, and autosomal vs. X chromosomal) and employ different methods (concatenation and coalescence analyses) to reconstruct the unresolved phylogeny of this diverse (∼7,000 spp.) and old (>180 Ma) group. Our results show that genes on the X chromosome are more likely to have discordant phylogenies than those on autosomes. We find that the X chromosome conflict is driven by high gene substitution rates that impact the accuracy of phylogenetic inference. However, gene tree clustering showed strong conflict even after discounting variable third codon positions. Alternative topologies were not particularly enriched for sex chromosome loci, but spread across the genome. We conclude that binning genes to autosomal or sex chromosomes may result in a more accurate picture of the complex evolutionary history of a clade.

Phylogenetic relationships and revised classification of the true bug infraorder Dipsocoromorpha (Insecta: Hemiptera: Heteroptera).

Currently comprising only about 430 species, Dipsocoromorpha or minute litter bugs are one of the small infraorders of Heteroptera. They are classified into five morphologically distinct families--Ceratocombidae, Dipsocoridae, Hypsipterygidae, Schizopteridae and Stemmocryptidae--but relationships among and within these families are poorly understood owing to the lack of phylogenetic studies. A phylogenetic hypothesis based on combined molecular and morphological data is important to both evaluate and revise the higher-level classification and to explore the evolutionary history of morphological features including elytriform (or beetle-like) forewings, that seem to have evolved multiple times in this group, jumping devices, and the highly modified and diverse male genitalia. We here use a dataset combining Sanger-derived (~4500 bp; 108 taxa) and Illumina-generated (~7500 bp; 24 taxa) sequence data with a morphological matrix (159 characters) and taxon sampling that comprises all currently recognized family-, subfamily- and tribal-level taxa and comprehensive genus-level sampling to investigate phylogenetic relationships within litter bugs. Our results support the monophyly of Dipsocoromorpha, Schizopteridae and Dipsocoridae, whereas Ceratocombidae and the schizopterine subfamily "Ogeriinae" are polyphyletic and paraphyletic, respectively. A new classification is proposed that recognizes six families, including Trichotonannidae, stat.n., and two subfamilies each within the two larger families Ceratocombidae and Schizopteridae. Ancestral state reconstructions outline the complex evolutionary history of many morphological characters, including 15 independent origins of elytriform forewings, and at least five shifts in the degree of genitalic asymmetry.

Phylogenomics and the evolution of hemipteroid insects.

Hemipteroid insects (Paraneoptera), with over 10% of all known insect diversity, are a major component of terrestrial and aquatic ecosystems. Previous phylogenetic analyses have not consistently resolved the relationships among major hemipteroid lineages. We provide maximum likelihood-based phylogenomic analyses of a taxonomically comprehensive dataset comprising sequences of 2,395 single-copy, protein-coding genes for 193 samples of hemipteroid insects and outgroups. These analyses yield a well-supported phylogeny for hemipteroid insects. Monophyly of each of the three hemipteroid orders (Psocodea, Thysanoptera, and Hemiptera) is strongly supported, as are most relationships among suborders and families. Thysanoptera (thrips) is strongly supported as sister to Hemiptera. However, as in a recent large-scale analysis sampling all insect orders, trees from our data matrices support Psocodea (bark lice and parasitic lice) as the sister group to the holometabolous insects (those with complete metamorphosis). In contrast, four-cluster likelihood mapping of these data does not support this result. A molecular dating analysis using 23 fossil calibration points suggests hemipteroid insects began diversifying before the Carboniferous, over 365 million years ago. We also explore implications for understanding the timing of diversification, the evolution of morphological traits, and the evolution of mitochondrial genome organization. These results provide a phylogenetic framework for future studies of the group.

Insight from an ultraconserved element bait set designed for hemipteran phylogenetics integrated with genomic resources.

Target enrichment of conserved genomic regions facilitates collecting sequences of many orthologous loci from non-model organisms to address phylogenetic, phylogeographic, population genetic, and molecular evolution questions. Bait sets for sequence capture can simultaneously target thousands of loci, which opens new avenues of research on speciose groups. Current phylogenetic hypotheses on the >103,000 species of Hemiptera have failed to unambiguously resolve major nodes, suggesting that alternative datasets and more thorough taxon sampling may be required to resolve relationships. We use a recently designed ultraconserved element (UCE) bait set for Hemiptera, with a focus on the suborder Heteroptera, or the true bugs, to test previously proposed relationships. We present newly generated UCE data for 36 samples representing three suborders, all seven heteropteran infraorders, 23 families, and 34 genera of Hemiptera and one thysanopteran outgroup. To improve taxon sampling, we also mined additional UCE loci in silico from published hemipteran genomic and transcriptomic data. We obtained 2271 UCE loci for newly sequenced hemipteran taxa, ranging from 265 to 1696 (average 904) per sample. These were similar in number to the data mined from transcriptomes and genomes, but with fewer loci overall. The amount of missing data correlates with greater phylogenetic divergence from taxa used to design the baits. This bait set hybridizes to a wide range of hemipteran taxa and specimens of varying quality, including dried specimens as old as 1973. Our estimated phylogeny yielded topologies consistent with other studies for most nodes and was strongly-supported. We also demonstrate that UCE loci are almost exclusively from the transcribed portion of the genome, thus data can be successfully integrated with existing genomic and transcriptomic resources for more comprehensive phylogenetic sampling, an important feature in the era of phylogenomics. UCE approaches can be used by other researchers for additional studies on hemipteran evolution and other research that requires well resolved phylogenies.

Revisiting habitat and lifestyle transitions in Heteroptera (Insecta: Hemiptera): insights from a combined morphological and molecular phylogeny.

Heteroptera, the true bugs, are part of the largest clade of non-holometabolous insects, the Hemiptera, and include > 42 000 described species in about 90 families. Despite progress in resolving phylogenetic relationships between and within infraorders since the first combined morphological and molecular analysis published in 1993 (29 taxa, 669 bp, 31 morphological characters), recent hypotheses have relied entirely on molecular data. Weakly supported nodes along the backbone of Heteroptera made these published phylogenies unsuitable for investigations into the evolution of habitats and lifestyles across true bugs. Here we present the first combined morphological and molecular analyses of Heteroptera since 1993, using 135 taxa in 60 families, 4018 aligned bp of ribosomal DNA and 81 morphological characters, and various analytical approaches. The sister-group relationship of the predominantly aquatic Nepomorpha with all remaining Heteroptera is supported in all analyses, and a clade formed by Enicocephalomorpha, Dipsocoromorpha and Gerromorpha in some. All analyses recover Leptopodomorpha + (Cimicomorpha + Pentatomomorpha), mostly with high support. Parsimony- and likelihood-based ancestral state reconstructions of habitats and lifestyles on the combined likelihood phylogeny provide new insights into the evolution of true bugs. The results indicate that aquatic and semi-aquatic true bugs invaded these habitats three times independently from terrestrial habitats in contrast to a recent hypothesis. They further suggest that the most recent common ancestor of Heteroptera was predacious, and that the two large predominantly phytophagous clades (Trichophora and Miroidea) are likely to have derived independently from predatory ancestors. We conclude that by combining morphological and molecular data and employing various analytical methods our analyses have converged on a relatively well-supported hypothesis of heteropteran infraordinal relationships that now requires further testing using phylogenomic and more extensive morphological datasets.

Phylogenetic comparative analysis supports aposematic colouration-body size association in millipede assassins (Hemiptera: Reduviidae: Ectrichodiinae).

The diversity of colour patterns and its importance in interactions with the environment make colouration in animals an intriguing research focus. Aposematic colouration is positively correlated with body size in certain groups of animals, suggesting that warning colours are more effective or that crypsis is harder to achieve in larger animals. Surprisingly, this relationship has not been recovered in studies investigating insects, which may have been confounded by a focus on aposematic taxa that are also gregarious. Millipede assassin bugs (Hemiptera: Reduviidae: Ectrichodiinae) comprise species with cryptic and aposematic colour patterns across a range of body sizes, are typically solitary as adults and are thus an excellent model for investigating a possible association between colouration and body size. Here, we use a comprehensive phylogeny for Ectrichodiinae, ancestral state reconstruction of colouration, and phylogenetic comparative methods to test for a colouration-body size association. The ancestor of Ectrichodiinae is reconstructed as cryptically coloured, with multiple subsequent transitions between aposematic and cryptic colouration. Aposematic colouration is positively associated with male body length and supports the hypothesis that selection on Ectrichodiinae body size may influence evolutionary transitions between aposematic and cryptic colouration or alternatively that selection for aposematic colouration influences body size evolution.

Molecular phylogenetics and biogeography of the ambush bugs (Hemiptera: Reduviidae: Phymatinae).

The ambush bugs (Heteroptera: Reduviidae: Phymatinae) are a diverse clade of predators known for their cryptic hunting behavior and morphologically diverse raptorial forelegs. Despite their striking appearance, role as pollinator predators, and intriguing biogeographic distribution, phylogenetic relationships within Phymatinae are largely unknown and the evolutionary history of the subfamily has remained in the dark. We here utilize the most extensive molecular phylogeny of ambush bugs to date, generated from a 3328 base pair molecular dataset, to refine our understanding of phymatine relationships, estimate dates of divergence (BEAST 2), and uncover historical biogeographic patterns (S-DIVA and DEC). This taxon set (39 species of Phymatinae and six outgroups) allowed reevaluation of the proposed sister group of Phymatinae and tribal-level relationships within the group, and for the first time proposes species-level relationships within Phymata Latreille, the largest genus of ambush bugs (∼109spp.). Available evidence suggests that Phymata originated in the Neotropical region, with subsequent dispersals to the Nearctic and Palearctic regions. This study provides a framework for future research investigating the evolutionary history of ambush bugs, as well as ecological and microevolutionary investigations.

Areas of endemism in the Nearctic: a case study of 1339 species of Miridae (Insecta: Hemiptera) and their plant hosts.

Areas of endemism are essential first hypotheses in investigating historical biogeography, but there is a surprising paucity of such hypotheses for the Nearctic region. Miridae, the plant bugs, are an excellent taxon to study in this context, because this group combines high species diversity, often small distribution ranges, a history of modern taxonomic revisions, and comprehensive electronic data capture and data cleaning that have resulted in an exceptionally error-free geospatial data set. Many Miridae are phytophagous and feed on only one or a small number of host plant species. The programs ndm/vndm are here used on plant bug and plant data sets to address two main objectives: (i) identify areas of endemism for plant bugs based on parameters used in a recent study that focused on Nearctic mammals; and (ii) discuss hypotheses on areas of endemism based on plant bug distributions in the context of areas identified by their host plant species. Given the narrow distribution ranges of many species of Miridae, the analytical results allow for tests of the prediction that areas of endemism for Miridae are smaller and more numerous, especially in the Western Nearctic, than are those of their host plants. Analyses of the default plant bug data set resulted in 45 areas of endemism, 35 of them north of Mexico and many located in the Western Nearctic; areas in the Nearctic are more numerous and smaller than those identified by mammals. The host plant data set resulted in ten areas of endemism, and even though the size range of areas is similar between the Miridae and plant data sets, the average area size is smaller in the Miridae data set. These results allow for the conclusion that the Miridae indeed present a valuable model system to investigate areas of endemism in the Nearctic.

Phylogenetic Evidence for Ancient and Persistent Environmental Symbiont Reacquisition in Largidae (Hemiptera: Heteroptera).

The insect order Hemiptera, one of the best-studied insect lineages with respect to bacterial symbioses, still contains major branches that lack comprehensive characterization of associated bacterial symbionts. The Pyrrhocoroidea (Largidae [220 species] and Pyrrhocoridae [∼300 species]) is a clade of the hemipteran infraorder Pentatomomorpha. Studies on bacterial symbionts of this group have focused on members of Pyrrhocoridae, but recent examination of species of two genera of Largidae demonstrated divergent symbiotic complexes in these putative sister families. We surveyed the associated bacterial diversity of this group using paired-end Illumina sequencing and targeted Sanger sequencing of bacterial 16S rRNA amplicons of 30 pyrrhocoroid taxa, including 17 species of Largidae, in order to determine bacterial associates and the similarity of associated microbial communities among species. We also used molecular data (4,800 bp in 5 loci, for 57 ingroup and 12 outgroup taxa) to infer a phylogeny of the host superfamily, in order to trace the evolution of symbiotic complexes among Pentatomomorpha species. We undertook multiple lines of investigation (i.e., experimental rearing, fluorescence in situ hybridization microscopy, and phylogenetic and coevolutionary analyses) to elucidate potential transmission routes for largid symbionts. We found a prevalent and specific association of Largidae with Burkholderia strains of the plant-associated beneficial and environmental clade, housed in midgut tubules. As in other distantly related Heteroptera, symbiotic bacteria seem to be acquired from the environment every generation. We review the current understanding of symbiotic complexes within Pentatomomorpha and discuss means to further investigate the evolution and function of these symbioses. IMPORTANCE: Obligate symbioses with bacteria are common in insects, particularly Hemiptera, in which various forms of symbiosis occur. However, knowledge regarding symbionts remains incomplete for major hemipteran lineages. Thus, an accurate understanding of how these partnerships evolved and changed over millions of years is not yet achievable. We contribute to our understanding of the evolution of symbiotic complexes in Hemiptera by characterizing bacterial associates of Pyrrhocoroidea, focusing on the family Largidae. Members of Largidae are associated with specific symbiotic Burkholderia strains from a different clade than Burkholderia symbionts in other Burkholderia-associated Hemiptera. Evidence suggests that species of Largidae reacquire specific symbiotic bacteria from the environment every generation, which is a rare strategy for insects, with potentially volatile evolutionary ramifications, but one that must have persisted in Largidae and related lineages since their origin in the Cretaceous Period.

Phylogenetics and biogeography of the endemic Madagascan millipede assassin bugs (Hemiptera: Reduviidae: Ectrichodiinae).

For at least the past 80my, Madagascar, a major biodiversity hotspot, has been isolated from all other landmasses. This long-term isolation, along with geologic and climatic factors within Madagascar and throughout the Indian Ocean, has undoubtedly influenced the evolution of the island's biota. However, few systematic analyses incorporating modern divergence dating and biogeographic analyses have focused on Madagascan insects. The diverse Madagascan millipede assassin bugs (Heteroptera: Reduviidae: Ectrichodiinae) offer an opportunity to contribute to a limited body of insect-related research that explores Madagascar's historical biogeography. A molecular dataset (COI mtDNA and 18S, 28S D2 and D3-D5 rDNAs) for 56 taxa (39 ingroup) and a combined morphological (145 characters) and molecular dataset for 110 taxa (93 ingroup) are analyzed with maximum likelihood (ML) and parsimony approaches. Based on the molecular ML phylogeny, divergence times were estimated using fossil and secondary calibrations and biogeographic analyses performed using DIVA, DEC, and DEC+j models to determine the role and patterns of vicariance and dispersal in the origin of Madagascan Ectrichodiinae. Results indicate that Ectrichodiinae in Madagascar do not form a monophyletic group, different clades are closely related to Afrotropical and Oriental lineages, and have colonized the island via transoceanic dispersal at least twice from the Oriental region and once from the Afrotropical region in the last ∼68my. Additionally, the DEC+j and DIVA models infer a single out-of-Madagascar dispersal event to the Afrotropical region. Oceanic and geologic factors that may have facilitated dispersal between these three regions are discussed. Results of the combined analyses are used to explore character support for Madagascan taxa and inform taxonomic diagnoses. Our results are congruent with the small but growing body of biogeographic research supporting Cenozoic transoceanic dispersal for Madagascan invertebrates to and from Oriental and Afrotropical regions.

Efficient capture of natural history data reveals prey conservatism of cryptic termite predators.

Stenophagy, specialization of a clade on a narrow range of taxa, has not been well studied in speciose clades of predators, principally due to the difficulty of obtaining adequate natural history data. The pantropical Salyavatinae (Hemiptera: Reduviidae; 17 genera, 107 species) contains members with enigmatic morphology and specialized behavior for feeding on termites. All Salyavatinae are suspected specialist termite predators; however, existing observations are limited to seven species. Prior analyses indicate that Salyavatinae may be paraphyletic with respect to another subfamily, Sphaeridopinae, also hypothesized to feed on termites. A molecular phylogeny of these putative termite assassins is here constructed using seven loci from 28 species in nine genera and is used in a dating analysis to shed light on the timing of Neotropical colonization by this primarily Old World clade. DNA extracted from gut contents of 50 individuals was assayed using PCR with prey-specific primers.Molecular assays, along with recent photographs and observations, provide substantial evidence that this clade feeds specifically upon termites, documenting 28 new individual associations. Our phylogeny supports a sister group relationship of the Neotropical genus Salyavata with Sphaeridopinae. Termite association data combined with our phylogeny provide evidence of previously unknown prey conservatism among clades of one of the most diverse groups of specialist termite predators.

Molecular phylogeny of Harpactorinae and Bactrodinae uncovers complex evolution of sticky trap predation in assassin bugs (Heteroptera: Reduviidae).

Sticky trap predation, the use of adhesive substances to trap and capture prey, is an intriguing yet poorly studied predatory strategy. Unique among known sticky trap predators, assassin bugs (Reduviidae) have evolved both exogenous and endogenous sticky trap predatory mechanisms: some trap their prey with sticky plant resins, some scavenge insects entrapped by sticky plant trichomes and others self-produce sticky secretions. The evolution of these different strategies in assassin bugs is poorly understood due to the lack of comprehensive phylogenies. We reconstruct a phylogeny of Reduviidae (141 taxa; > 5000 bp) focusing on the Harpactorinae and Bactrodinae that engage in sticky trap predation. Ancestral state reconstruction, and temporal and geographical divergence analyses show that sticky trap predation techniques in assassin bugs evolved at least seven times independently since the late Cretaceous: use of sticky plant trichomes evolved as many as four times, resin-use twice independently and once as a transition from trichome use, and 'self-stickiness' once. Exogenous and endogenous sticky traps first appeared in the Neotropics, with the two exogenous mechanisms (resin and trichome use) subsequently evolving independently in the Old World. This study illustrates, for the first time, the complex evolutionary pattern of sticky trap predation within assassin bugs.

Reduvius frommeri, a new species of Reduviidae from the Western United States (Hemiptera: Reduviidae), with a synopsis of the Nearctic species of Reduvius Fabricius.

The rate of discovery of new species of Reduviidae (Insecta: Heteroptera) from North America has slowed in the 21st century. This is not surprising, given the conspicuousness and large distribution ranges of many Nearctic assassin bug species that are often collected using general insect collecting techniques. Nevertheless, biodiversity discovery in Nearctic Reduviidae is ongoing. We here describe a new species, Reduvius frommeri, n. sp., from Southern California that is so far only known from a small endemic range in the Sonoran Desert. With about 197 species, the genus Reduvius Fabricius is one of the most speciose genera of Reduviidae. The majority of species occur in arid- and semi-arid areas in the Afrotropical, Oriental, and Palearctic regions and only three species are New World endemics. A fourth species that occurs in the United States, Reduvius personatus Fabricius, is cosmopolitan and has been introduced to the Western Nearctic. The new species of Reduvius stands out amongst the four other Nearctic Reduvius species by the small size and pale body coloration with a contrasting dark head. Image plates documenting habitus and selected morphological details and maps are provided for the five species in the Nearctic. We conclude that efforts to document species diversity and distribution ranges even for conspicuous insects such as assassin bugs in fairly well studied biogeographic regions need to continue.

Molecular phylogeny of Harpactorini (Insecta: Reduviidae): correlation of novel predation strategy with accelerated evolution of predatory leg morphology.

Much research and discussion have focused on the effects of key innovations on lineage diversification, whereas little has been done to investigate their role in morphological evolution using phylogenetic approaches. Here we present the first comprehensive molecular phylogeny of the Harpactorini (Insecta: Reduviidae), the largest assassin bug tribe, sampling 229 terminal taxa and using five gene segments (28S D2, D3-D5, 16S, COI, and Deformed). Employing comparative phylogenetic methods, we demonstrate the correlation of a putative key innovation, the sticky trap predation strategy, with accelerated rates of morphological evolution of the predatory fore leg in assassin bugs. We show that bugs exhibiting sticky trap predation have evolved more slender and longer fore femora than non-sticky bugs. Using phylogenetically independent contrast analyses, we document correlated evolution between femoral thickness and length. We argue that the novel sticky trap predation strategy may allow sticky bugs to alleviate functional constraints on the fore femur and thus to attain a higher rate of evolution than other Harpactorini or Reduviidae. We discuss the possibility that sticky bugs represent a case of adaptive radiation. We also test historical supra-generic groups within the Harpactorini, and show that most of them are not monophyletic. We confirm the paraphyly of Harpactorini with respect to Rhaphidosomini.

Structure and bioactivity of an insecticidal trans-defensin from assassin bug venom.

Disulfide-rich peptides such as defensins play diverse roles in immunity and ion channel modulation, as well as constituting the bioactive components of many animal venoms. We investigated the structure and bioactivity of U-RDTX-Pp19, a peptide previously discovered in venom of the assassin bug Pristhesancus plagipennis. Recombinant Pp19 (rPp19) was found to possess insecticidal activity when injected into Drosophila melanogaster. A bioinformatic search revealed that domains homologous to Pp19 are produced by assassin bugs and diverse other arthropods. rPp19 co-eluted with native Pp19 isolated from P. plagipennis, which we found is more abundant in hemolymph than venom. We solved the three-dimensional structure of rPp19 using 2D 1H NMR spectroscopy, finding that it adopts a disulfide-stabilized structure highly similar to known trans-defensins, with the same cystine connectivity as human α-defensin (I-VI, II-IV, and III-V). The structure of Pp19 is unique among reported structures of arthropod peptides.

Systematics and evolution of Heteroptera: 25 years of progress.

Heteroptera, or true bugs, are part of the most successful radiation of nonholometabolous insects. Twenty-five years after the first review on the influence of cladistics on systematic research in Heteroptera, we summarize progress, problems, and future directions in the field. The few hypotheses on infraordinal relationships conflict on crucial points. Understanding relationships within Gerromorpha, Nepomorpha, Leptopodomorpha, Cimicomorpha, and Pentatomomorpha is improving, but progress within Enicocephalomorpha and Dipsocoromorpha is lagging behind. Nonetheless, the classifications of several superfamily-level taxa within the Pentatomomorpha, such as Aradoidea, Coreoidea, and Pyrrhocoroidea, are still unaffected by cladistic studies. Progress in comparative morphology is slow and drastically impedes our understanding of the evolution of major clades. Molecular systematics has dramatically contributed to accelerating the generation and testing of hypotheses. Given the fascinating natural history of true bugs and their status as model organisms for evolutionary studies, integration of cladistic analyses in a broader biogeographic and evolutionary context deserves increased attention.

Taxonomic revision of the Apiomerus maya species group (Heteroptera: Reduviidae: Harpactorinae).

The Apiomerus maya species group of the genus Apiomerus Hahn, 1831 (Hemiptera: Heteroptera: Reduviidae: Harpactorinae: Apiomerini), the bee assassins, is revised. Four species that are native to parts of Mexico and Central America are recognized and redescribed: Apiomerus maya Dispons, 1971, A. pipil Dispons, 1971, A. venosus Stl, 1872, and A. immundus Bergroth, 1898. Intraspecific polychromatism and male genital morphology are documented for the group. The taxonomy of two previously recognized species is updated: A. tristis Champion, 1899 syn. nov. is here synonymized with A. venosus and A. guatemalensis Dispons, 1971 syn. nov. with A. pipil.

On the evolution of raptorial legs - an insect example (Hemiptera: Reduviidae: Phymatinae).

The presence of chelate and subchelate fore legs in Phymatinae (Hemiptera: Reduviidae), or ambush bugs, provides a unique opportunity to study the evolution of different types of raptorial legs in a closely related group of arthropods. Themonocorini have simple, possibly raptorial legs, Phymatini and Macrocephalini distinct subchelate fore legs, and the charismatic Carcinocorini are the only insects with a chelate fore leg apart from female dryinid Chysidoidea (Hymenoptera). Relationships between the four phymatine tribes are here analyzed in a cladistic framework thus permitting testable hypotheses on the evolution of raptorial legs. The presented analysis of phymatine tribal level relationships is based on a dataset comprising 11 species of Phymatinae and 54 non-phymatine Reduviidae and Heteroptera. The molecular data set consists of ∼3500 MAFFT aligned bases of 16S, 28S D2-D3, and 18S ribosomal genes. Parsimony and maximum likelihood analyses resulted in identical topologies for the ingroup with the relationships Themonocorini + (Phymatini + (Carcinocorini + Macrocephalini)) receiving high support values. Eleven morphological characters, eight of them derived from fore leg morphology, were optimized on the parsimony analysis. These optimizations indicate that the ancestral ambush bug had a simple raptorial leg; that size reduction of the tarsus, enlargement of the femur, curvature of the fore tibia, armature of tibia and femur with rows of tiny tubercles that allow for gripping of a prey insect, and the large process on the ventral surface of the femur arose in the common ancestor of Carcinocorini + Macrocephalini + Phymatini. The chelate leg in Carcinocorini is likely derived from a subchelate precursor similar to the one seen in recent Macrocephalini and may have evolved through elongation of the ventral, proximal portion of the fore femur and modification of the median process to form part of the digitus fixus. © The Willi Hennig Society 2010.

New alignment-based sequence extraction software (ALiBaSeq) and its utility for deep level phylogenetics.

Despite many bioinformatic solutions for analyzing sequencing data, few options exist for targeted sequence retrieval from whole genomic sequencing (WGS) data with the ultimate goal of generating a phylogeny. Available tools especially struggle at deep phylogenetic levels and necessitate amino-acid space searches, which may increase rates of false positive results. Many tools are also difficult to install and may lack adequate user resources. Here, we describe a program that uses freely available similarity search tools to find homologs in assembled WGS data with unparalleled freedom to modify parameters. We evaluate its performance compared to other commonly used bioinformatics tools on two divergent insect species (>200 My) for which annotated genomes exist, and on one large set each of highly conserved and more variable loci. Our software is capable of retrieving orthologs from well-curated or unannotated, low or high depth shotgun, and target capture assemblies as well or better than other software as assessed by recovering the most genes with maximal coverage and with a low rate of false positives throughout all datasets. When assessing this combination of criteria, ALiBaSeq is frequently the best evaluated tool for gathering the most comprehensive and accurate phylogenetic alignments on all types of data tested. The software (implemented in Python), tutorials, and manual are freely available at https://github.com/AlexKnyshov/alibaseq.

Taxonomic revision of emGuapinannus/em Wygodzinsky, 1951 (Hemiptera: Schizopteridae), with description of 19 new species.

Guapinannus Wygodzinsky, 1951 (Hemiptera: Schizopteridae) was described based on a single female specimen from Costa Rica. Some additional specimens representing this genus have since become available and were incorporated into a comparative male genitalic study across Dipsocoromorpha and into combined molecular and morphological hypotheses of the infraorder. However, the species-level diversity of Guapinannus has remained unexplored and undocumented. Based on examination of 264 specimens from central and South America, we here revise the taxonomy of Guapinannus, describing 19 species as new (Guapinannus anaticulus, sp. n.; Guapinannus artus, sp. n.; Guapinannus auriculus, sp. n.; Guapinannus castigatus, sp. n.; Guapinannus clava, sp. n.; Guapinannus dispar, sp. n.; Guapinannus falcis, sp. n.; Guapinannus graziae, sp. n.; Guapinannus minutus, sp. n.; Guapinannus orbiculatus, sp. n.; Guapinannus plurilobus, sp. n.; Guapinannus policis, sp. n.; Guapinannus robustus, sp. n.; Guapinannus sinuosus, sp. n.; Guapinannus tatumbia, sp. n.; Guapinannus tenuis, sp. n.; Guapinannus tergus, sp. n.; Guapinannus trilobus, sp. n.; Guapinannus uncus, sp. n.). In addition, we provide photos of the female holotype of Guapinannus bierigi Wygodzinsky, 1951, SEM documentation for Guapinannus clava, sp. n., habitus photos and a map for all species, and line drawings of male genitalic features for all species for which males are known.