Heteroptera research in Latin America and the Caribbean (Insecta, Hemiptera): status and perspectives in the 21st century.

Latin American and the Caribbean regions (LAC) harbor one of the most biodiverse areas of the world, the Neotropics. True bugs (Hemiptera: Heteroptera) are a diverse lineage of insects, with more than 45,000 species, particularly speciose in the Neotropical region. True bugs are fundamental in the dynamics of natural and modified ecosystems, with several species critical to agriculture and public health. We compiled Heteroptera research in LAC from 1998-2022 using bibliographic databases. Productivity, collaborative networks, and the main topics studied were analyzed. A total of 1,651 Heteroptera studies from LAC were found, with continuous growth being 2021 the most prolific. Four categories (Taxonomy of extant species, Faunistic inventories and new records, Pest species biology, and Community ecology) represent most of the published research. About 60 percent of the records evaluated correspond to five families (Pentatomidae, Reduviidae, Coreidae, Miridae, and Rhyparochromidae). We emphasize the need to keep working on Heteroptera taxonomy because it will allow further advances in other areas such as phylogenetic analyses, biogeography, ecology, and natural history, among others. The results of our analyses characterize the current state of heteropterology in the region, establishing a baseline for future studies and efforts to broaden the knowledge of the group.

Barcoding a can of worms: testing cox1 performance as a DNA barcode of Nematoda.

Accurate taxonomic identifications and species delimitations are a fundamental problem in biology. The complex taxonomy of Nematoda is primarily based on morphology, which is often dubious. DNA barcoding emerged as a handy tool to identify specimens and assess diversity, but its applications in Nematoda are incipient. We evaluated cytochrome c oxidase subunit I (cox1) efficiency as a DNA barcode for nematodes scrutinising 5241 sequences retrieved from BOLD and GenBank. The samples included genera with medical, agricultural, or ecological relevance: Anguillicola, Caenorhabditis, Heterodera, Meloidogyne, Onchocerca, Strongyloides, and Trichinella. We assessed cox1 performance through barcode gap and Probability of Correct Identification (PCI) analyses, and estimated species richness through Automatic Barcode Gap Discovery (ABGD). Each genus presented distinct gap ranges, mirroring the evolutionary diversity within Nematoda. Thus, to survey the diversity of the phylum, a careful definition of thresholds for lower taxonomic levels should be considered. PCIs were around 70% for both databases, highlighting operational biases and challenges in nematode taxonomy. ABGD inferred higher richness than the taxonomic labels informed by databases. The prevalence of specimen misidentifications and dubious species delimitations emphasise the value of integrative approaches to nematode taxonomy and systematics. Overall, cox1 is a relevant tool for integrative taxonomy of nematodes.

Getting science priorities straight: how to increase the reliability of specimen identification?

'We advise the authors to find a native English speaker to proofread the manuscript'. This is a standard feedback journals give to non-native English speakers. Journals are justifiably concerned with grammar but do not show the same rigour about another step crucial to biological research: specimen identification. Surveying the author guidelines of 100 journals, we found that only 6% of them request explicitly citation of the literature used in specimen identification. Authors hamper readers from contesting specimen identification whenever vouchers, identification methods, and taxon concepts are not provided. However, unclear taxonomic procedures violate the basic scientific principle of reproducibility. The scientific community must continuously look for practical alternatives to improve taxonomic identification and taxonomic verification. We argue that voucher pictures are an accessible, cheap and time-effective alternative to mitigate (not abolish) bad taxonomy by exposing preventable misidentifications. Voucher pictures allow scientists to judge specimen identification actively, based on available data. The popularization of high-quality image devices, photo-identification technologies and computer vision algorithms yield accurate scientific photo-documentation, improving taxonomic procedures. Taxonomy is timeless, transversal and essential to most scientific disciplines in biological sciences. It is time to demand rigour in taxonomic identifications.

External egg structure of the Pentatomidae (Hemiptera: Heteroptera) and the search for characters with phylogenetic importance.

The chorionic structure of sixteen pentatomid species is described. Morphological patterns in different taxonomic levels are discussed. In addition, egg characters useful in cladistic analyses are listed, and some of those characters are tested for congruence with two cladistic analyses previously conducted within Pentatomidae. Descriptive studies were conducted with Banasa induta, Capivaccius bufo, Catulona pensa, Chinavia armigera, Chinavia aseada, Chinavia brasicola, Chinavia runaspis, Dichelops furcatus, Euschistus heros, Euschistus riograndensis, Euschistus paranticus, Mormidea cornicollis, Podisus distinctus, Podisus nigrispinus, Serdia apicicornis, and Thoreyella maracaja. The eggs were examined and photographed under light and scanning electron microscopy. Based on literature data, a list of 40 egg characters with potential phylogenetic importance has been compiled. Some of these characters were included in the cladistic analyses of the genus Nezara (six characters) and of the Chinavia obstinata group (five characters). Both analyses were performed in TNT with equal weighting of characters. The eggs of most of the Neotropical species studied were barrel-shaped, chorion translucent and spinose, with aero-micropylar processes that were short and clubbed. The patterns of egg morphology could be identified in Carpocorini, Procleticini, and in the genera Banasa, Chinavia, Euschistus, Mormidea, and Podisus. In the cladistic analyses, the inclusion of egg characters did not affect the topology of the trees shown in the original papers. For the analyses, the egg characters were somewhat informative. At present, a total of 286 Pentatomidae species have their egg stage described. 

Four new stink bug mitogenomes corroborate the internal inconsistencies in the classification of Pentatomidae (Hemiptera).

Stink bugs (Pentatomidae) are a speciose group of insects that feed mostly on plants. Many species are considered agricultural pests of economically important crops around the globe. Mitochondrial genomes are valuable for evolutionary and phylogenetic studies, but have been little explored for Pentatomidae. Here, we characterized the mitochondrial genomes of four pentatomid species (Diceraeus melacanthus, Euschistus heros, Piezodorus guildinii, and Stiretrus anchorago) and performed a comparative analysis for this family and its subfamilies. Stink bug mitogenomes disclosed a conserved gene order and content, although we detected two uncommon armless tRNAs in E. heros and D. melacanthus. Phylogenetic results indicate that Pentatominae is polyphyletic, showing that internal relationships of Pentatomidae should be further investigated. Stink bug mitochondrial genes are under strong purifying selection, except for ATP8 which showed signs of positive selection.

A giant within Carpocorini (Hemiptera: Heteroptera: Pentatomidae): Description of emAdustonotus/em emgraziae/em sp. nov.

The Carpocorini are distributed worldwide, and it is one of the most speciose tribes within the Pentatomidae with 127 genera and more than 500 valid species. Recently, Adustonotus Bianchi was described to contain eight species formerly placed within Euschistus Dallas. Among them, Adustonotus grandis (Rolston) and Adustonotus latus (Dallas) are remarkable for their large size. Herein, the phylogenetic position of a new taxon is inferred by a total evidence analysis based on 85 morphological characters and four molecular markers. Adustonotus graziae sp. nov. is described, and is recovered in a polytomic lineage, including A. grandis and A. latus. These species share a solid combination of features that enable them to be separated from the other Adustonotus species (e.g., large size, the humeral angles spatulate and exceptionally produced, and the capsula seminalis shortened). Illustrations of external and internal genitalia, and a distributional map are provided.

A milestone for Pentatomoidea: Grazia emet al./em 2008-What do we know and where can we go?

Pentatomoidea is the third largest superfamily in Heteroptera. The internal systematics and classification of this superfamily have an intricate history. The paper by Grazia et al. (2008) is a milestone to the phylogenetic hypothesis of Pentatomoidea. Subsequent papers explored the limited conclusions and unanswered questions left by Grazia et al. (2008). We proposed to look at the body of knowledge produced since Grazia et al. (2008) and to compile the molecular data for Pentatomoidea deposited in Genbank to achieve three aims: (i) to evaluate the advances on the phylogenetic relationships of the Pentatomoidea; (ii) to produce a phylogenetic hypothesis based on molecular data deposited in Genbank; and (iii) to highlight the shortcomings and strengths of the available data. We retrieved sequences of four molecular markers (COI, 16S, 18S, and 28S) for 167 terminal taxa, including 149 pentatomoids. A concatenated matrix was analyzed under maximum likelihood (ML) and parsimony (MP). Both methods supported the monophyly of Pentatomoidea, and poorly resolved internal relationships among the families. Acanthosomatidae, Dinidordae, Pentatomidae, Scutelleridae, Thaumastellidae, and Urostylididae were monophyletic (under ML and MP), and also Plataspidae and Thyreocoridae (under ML). Tessaratomidae and Cydnidae were non-monophyletic under both methods. Our results were compared to the phylogenetic hypotheses proposed for Pentatomoidea. The analysis of the data available on the GenBank allowed us to affirm that many problems mentioned previously remain unsolved, even though the sampling of terminals has increased. In summary, the efforts in the last two decades to better understand the relationships within the Pentatomoidea have been insufficient to propose robust advances in phylogenetic hypothesis for the group. We discuss topics we understand are paramount to upcoming developments:1) better taxon sample; 2) collection management; 3) increased markers; and 4) morphology and anatomical ontology.

Finding Padaeus bovillus (Hemiptera: Pentatomidae): A Phylogenetic Placement and the Description of Its Sister Species.

The pentatomids (Hemiptera: Heteroptera) are the third most speciose family within the Heteroptera or the true bugs. The family occurs worldwide and comprises around five thousand valid species within 950 genera. Padaeus Stål belongs to a complex of other genera of Carpocorini Mulsant and Rey related to Euschistus Dallas. These genera present similarities in color, size, and shape, and share common features. However, among its four congeneric species, Padaeus bovillus Distant has been highlighted as an outlier by the posterior margins of the bucculae evanescent, while its congeneric species present posterior margins of the bucculae lobed. Thus, herein we redescribe P. bovillus and present a hypothesis regarding its phylogenetic placement within the Carpocorini. Furthermore, a new species similar to P. bovillus is described. Four molecular markers (COI, CytB, 16S, and 28S) plus 86 morphological characters were used to infer the phylogeny under Maximum likelihood and Bayesian inference. For the descriptions, we measured 16 morphometric parameters and dissected the genitalic structures. We also include illustrations of the habitus, internal and external genitalic structures, and provide distribution maps. Mitripus seclusus sp. n. Bianchi, Krein, Rider, and Grazia is recovered as the sister species to Mitripus bovillus comb. n., and both within Mitripus Rolston. Among other shared characters, species of Mitripus have the femora unarmed, they have a macula near the apex of the radial vein, and the mandibular plates tapering apically. Mitripus bovillus comb. n. and Mitripus seclusus sp. n. have the posterior margin of the pygophore projecting as a spine, a unique pattern within the genus. According to our results, Mitripus including M. bovillus comb. n. and Mitripus seclusus sp. n. now includes five species.

Integrating data to redescribe Euschistus taurulus Berg (Hemiptera: Pentatomidae).

The genus Euschistus Dallas includes 67 species restricted to the New World, and several species are registered on cultivated plants in the Nearctic and Neotropical regions. In South America, most Euschistus species are completely overlooked due to the lack of information to allow accurate identification. Here, we redescribed Euschistus taurulus Berg, including for the first time, characterization of the internal and external genitalia of both sexes. We also report original information on bionomics, review and update information on geographical distribution and host plants records. Additionally, we provide DNA barcoding sequences for E. taurulus and three other morphologically similar key-agriculture pest species in South America: Euschistus heros (Fabricius), Dichelops melacanthus (Dallas), and Dichelops furcatus (Fabricius). We discuss means for correct identification of E. taurulus and its phylogenetic position within Euschistus and other similar stink bugs; the potential economic importance of the E. taurulus is also addressed.

Review of the sulcacitus group of Euschistus (Pentatomidae: Pentatominae: Carpocorini) with description of the internal female genitalia and a new species.

Euschistus Dallas is comprised of 66 species in three subgenera. Species of the nominate subgenus occur mainly in Central and North America. Some groups of species have been proposed to Euschistus (Euschistus) based on general external and male genitalic morphologies. Here, we review the sulcacitus group providing illustrations and descriptions of the internal and external genitalia of both sexes, illustrating females for the first time. A new species, Euschistus (Euschistus) tacitus sp. nov. Bianchi & Grazia, from Mexico and Costa Rica is described. We also provide an identification key to species of the group.

Description of three new species of Glyphepomis Berg (Heteroptera: Pentatomidae: Pentatominae).

Three new species of the Glyphepomis are described: Glyphepomis dubia Campos & Souza, sp. nov., Glyphepomis amazonica Gonçalves & Campos, sp. nov. and Glyphepomis magnocephala Bianchi & Campos, sp. nov. Comparative illustrations of external and internal genitalia, distribution map of the described species, additions to the genus description, and a key to the species are provided.

New species of Euschistus (Euschistus) from Jamaica, Euschistus (Mitripus) and Ladeaschistus from southern South America (Hemiptera: Heteroptera: Pentatomidae: Pentatominae).

Three new species of the Carpocorini are described: Euschistus (Euschistus) baranowskii Eger & Bianchi sp. nov. from Jamaica, Euschistus (Mitripus) saramagoi Bianchi, Cioato & Grazia sp. nov. from Brazil, and Ladeaschistus borgesi Bianchi, Cioato & Grazia sp. nov. from Argentina, Bolivia and Brazil. Comparative illustrations of external and internal genitalia of the species are provided.

Contributions to the knowledge of Banasa Stål (Hemiptera, Heteroptera, Pentatomidae): Banasa chaca Thomas

Contributions to the knowledge of Banasa Stål (Hemiptera, Heteroptera, Pentatomidae): Banasa chaca Thomas. The male of Banasa chaca Thomas is described with emphasis on external and internal genitalia and the female internal genitalia is described. Banasa chaca is newly recorded from Buenos Aires Province (Argentina).

Contribuições ao conhecimento de Banasa Stål (Hemiptera: Heteroptera: Pentatomidae: Pentatominae): Banasa chaca Thomas. O macho de Banasa chaca Thomas é descrito com ênfase na genitália externa e interna, também é descrita a genitália interna da fêmea. Banasa chaca é registrada pela primeira vez na província de Buenos Aires (Argentina).