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A select group of hemipterans within the suborder Auchenorrhyncha are the only animals that feed exclusively on xylem sap - a nutritionally poor liquid that exists under negative pressure within a plant's xylem vessels. To consume it, xylem-feeding bugs have evolved enlarged cibarial pumps capable of generating enormous negative pressures. A previous study examining the allometry of this feeding model suggested that small xylem feeders pay relatively higher energetic costs while feeding, favouring the evolution of larger-bodied species. However, this interspecific analysis only considered adult xylem-feeding insects and neglected the considerable intraspecific change in size that occurs across the insect's development. Here, we examine the changes in cibarial pump morphology and function that occur during the development of Philaenus spumarius, the common meadow spittlebug. We show that the cibarial pump scales largely as expected from isometry and that the maximum negative pressure is mass independent, indicating that size has no effect on the xylem-feeding capacity of juvenile spittlebugs. We conclude that a first instar nymph with a body mass 2% of the adult can still feed at the >1 MPa tension present in a plant's xylem vessels without a substantial energetic disadvantage., Competing Interests: Competing interests The authors declare no competing or financial interests., (© 2024. Published by The Company of Biologists Ltd.)

The subgenus Aeschyntelus includes six species that show variations in body color and shape, thus making it difficult to identify them based on morphological identification alone. To date, no genetic study has evaluated species within this genus. Herein, we collected 171 individuals from 90 localities of Rhopalus and employed an integrative taxonomic approach that incorporated morphological data, mitochondrial genomic data (COI, whole mitochondrial data) and nuclear genomic data (18S + 28S rRNAs, nuclear genome-wide SNPs) to delineate species boundaries. Our analyses confirmed the status of nine described species of Rhopalus and proposed the recognition of one new species known as Rhopalus qinlinganus sp. nov., which is classified within the subgenus Aeschyntelus. Discrepancies arising from nuclear and mitochondrial data suggest the presence of mito-nuclear discordance. Specifically, mitochondrial data indicated admixture within Clade A, comprising R. kerzhneri and R. latus, whereas genome-wide SNPs unambiguously identified two separate species, aligning with morphological classification. Conversely, mitochondrial data clearly distinguished Clade B- consisting of R. sapporensis into two lineages, whereas genome-wide SNPs unequivocally identified a single species. Our study also provides insights into the evolutionary history of Aeschyntelus, thus indicating that it likely originated in East Asia during the middle Miocene. The development of Aeschyntelus biodiversity in the southwestern mountains of China occurred via an uplift-driven diversification process. Our findings highlight the necessity of integrating both morphological and multiple molecular datasets for precise species identification, particularly when delineating closely related species. Additionally, it reveals the important role of mountain orogenesis on speciation within the southwestern mountains of China., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Inc.)

The Australian plant bug tribe Austromirini consists of ant-mimetic taxa which are poorly known, with no information of their phylogenetic relationships and ant-mimetic traits. In this study, we examined nearly 1000 ingroup specimens and developed a comprehensive morphological dataset comprising 37 characters, which was analysed both weighted and unweighted, using 'Tree analysis using New Technology' (TNT ) software. A single minimal length phylogenetic tree was found, comprising a monophyletic group of ant-mimetic taxa, that included Myrmecoroides rufescens , Myrmecoridea sp., Kirkaldyella spp. and eight species of a new genus, Carenotus gen. nov. The myrmecomorphic traits of Carenotus and allied ant-mimetic taxa are documented and analysed phylogenetically, in conjunction with genitalic characters. Carenotus is defined by the myrmecomorphic colour patterning of the abdominal venter, whereas the ingroup species relationships are supported by genitalic characters alone. Carenotus is described as new with eight included species as follows: C. arltunga sp. nov., C. louthensis sp. nov., C. luritja sp. nov., C. pullabooka sp. nov., C. scaevolaphilus sp. nov., C. schwartzi sp. nov., C. tanami sp. nov. and C. yuendumu sp. nov. Host plant associations are also documented, ranging from host plant specificity and genus-group preferences to host plant generalism. The distribution of Carenotus species is documented with reference to phytogeographic subregions, with all species being semi-arid and arid dwelling. The male and female genitalia of Kirkaldyella pilosa and K. rugosa are described and illustrated, for comparative and phylogenetic purposes. This research expands our knowledge on the plant bug tribe Austromirini and has broader implications for myrmecomorphic research in the suborder Heteroptera. ZooBank: urn:lsid:zoobank.org:pub:2FF9BE23-38A6-42B4-8488-74F216D8237F.

A trichobothrium is a complex sensory organ, which usually consists of a long, slender mechanoreceptive seta (trich), which is situated in a cuplike depression in the cuticle (bothrium). Nabidae (Hemiptera: Heteroptera: Cimicomorpha), also called damsel bugs, are a relatively small family within which two subfamilies, Nabinae and Prostemmatinae, are distinguished. Trichobothria are present in the number of one to seven pairs located laterally on the scutellum of adult representatives of Prostemmatinae. This feature is commonly used to distinguish this subfamily from Nabinae. Trichobothria are also found on the abdominal tergites of Prostemmatinae nymphs. Similar sensilla have been observed in adult representatives of Nabinae, but their homology has not yet been confirmed. During morphological studies on Nabidae, conducted using scanning electron microscopy, we noticed sensilla resembling trichobothria on the heads of these insects. This discovery prompted us to examine the presence of these structures in damsel bugs more carefully. Imagines of fifteen species of both subfamilies were analysed using a scanning electron microscope. The results present data on the distribution and micromorphology of the trichobothria in damsel bugs. A pair of dorsal and ventral cephalic trichobothria were observed in all of the examined species of subfamily Nabinae. These sensilla were not found on the heads of Prostemmatinae. The results of studies on scutellar trichobothria confirmed the previously known data regarding their occurrence in Prostemmatinae. Moreover, our research showed the presence of these sensory structures in all of the examined Nabinae species: one pair of trichobothria in Arachnocorini, Carthasini, Gorpini and Nabini, and two pairs in Stenonabini. The presence of abdominal trichobothria was shown in Nabini and Stenonabini. In the remaining studied tribes of Nabinae and in the subfamily Prostemmatinae, the presence of structures that could undoubtedly be considered abdominal trichobothria was not found., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

The Mecocephala group comprises about 50 species, restricted to the Neotropics and with the highest species richness in Neotropical South America. Several species use rice as host plants and their identification is facilitated by the presence of exaggerated head proportions and a unique male genitalic morphology. The taxonomy of the group has been extensively explored, but inferring its monophyly and especially its internal phylogenetic relationships has been challenging. Here, we inferred the phylogenetic relationships for the group assembling the most complete taxonomic sampling to date, analyzing discrete and continuous morphological characters through equal and implied weighted parsimony analyses. The monophyly of the group was recovered, but internal relationships varied slightly according to the dataset tested. Thus, we propose internal arrangements for the group and provide a formal description of the Mecocephala group, diagnoses for each genus, a dichotomous key to identify its genera, and illustrations of the morphological characters and type species., (© 2024. Sociedade Entomológica do Brasil.)

The genus Coridius Illiger, 1807 (Heteroptera: Dinidoridae) comprises a group of phytophagous terrestrial bugs consisting of 36 species distributed in the Afrotropical and Indo-Malayan regions. In several communities in northeastern India, insects are recognised as a delicacy, medicine, and a nutritional supplement, with Coridius being a popular delicacy. However, Coridius has received little taxonomic attention to date due to large intraspecific variations, inadequate taxonomic treatments, and the rarity of many species. To address this gap, an integrative taxonomy of the genus was performed. Two mitochondrial genes, viz., cytochrome oxidase subunit 1 (COI) and 16S rRNA, were sequenced to reconstruct the phylogenetic relationships within Coridius. We performed both maximum likelihood (ML) and Bayesian inference (BI) to develop a species tree, followed by the Bayesian implementation of the Poisson tree process (bPTP) and Assemble Species by Automatic Partitioning (ASAP) as an additional test to assess species boundaries and delimit operational taxonomic units. A linear discriminant analysis (LDA) of four key morphological characters was then performed to identify species groups. Overall, our analysis supported the establishment of three new species: Coridius adii sp. nov., Coridius esculentus sp. nov., and Coridius insperatus sp. nov., and revealed six distinct lineages within Coridius chinensis (Dallas, 1851). Linear discriminant analysis of morphological characters indicated the clustering of eight species. The species status of Coridius nigriventris (Westwood, 1837) stat. rev, formerly synonymized under Coridius nepalensis (Westwood, 1837), is reinstated in this study. Further, we revised the genus Coridius from India and rediscovered Coridius assamensis (Distant, 1902) and Coridius fuscus (Westwood, 1837) after 100 years., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Boyane et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Functional traits reveal the adaptive strategies of species to their environment, and are relevant to the formation of communities, the function of ecosystems, and the mechanisms underlying biodiversity. However, trait databases have not been established for most biological taxa, especially for insects, which encompass a vast number of species. This study measured the morphological traits of 307 species of Heteroptera insects collected in 2019 from the "Xishuangbanna Priority Conservation Area" in Southwest China using sweep netting and light trapping methods. This study provides a dataset for 307 Heteroptera species, comprising 34 morphometric measurements and 17 morphological traits. The dataset contains information on species sex, abundance, and the average, maximum, and minimum values of traits. This dataset facilitates an enhanced understanding of the functional traits and ecological associations of Heteroptera insects and offers opportunities for exploring a more diverse range of research topics., (© 2024. The Author(s).)

Here, we describe for the first time the sperm morphology of Tingidae (Heteroptera). They are small insects presenting lacy patterns on their pronotum and hemielytra and are exclusively phytophagous, with many economically important species. We studied five species of the tribe Tingini (Tinginae): Teleonemia scrupulosa, Vatiga illudens, Gargaphia lunulata, Leptopharsa sp., and Corythucha arcuata. Their spermiogenesis process is similar to other Heteroptera, with some differences in the formation of the centriole adjunct. This structure extends in the anteroposterior spermatid axis, flanking the nucleus, possibly contributing to nucleus remodeling and sperm elongation. The mature sperm of Tingidae is also similar to that of other Heteroptera, with features that corroborate the group's monophyly. Our data support previous results for their sister family, Miridae, which exhibits some characteristics exclusive to this taxon, not present in Tingidae or other Heteroptera. They also support the sister relationship of the genera Gargaphia and Leptopharsa and suggest closer relationship between Vatiga and Corythucha. Overall, this study sheds light on the sperm ultrastructure of Tingidae and provides information for understanding the evolution and diversity of Heteroptera. RESEARCH HIGHLIGHTS: The spermiogenesis process and mature sperm are similar to other Heteroptera The centriole adjunct is derived from a strip of a pericentriolar material extending from the centriole Tingidae and Miridae are distinguishable using sperm morphology., (© 2024 Wiley Periodicals LLC.)

Taxonomic data on Coreidae have been fragmented over time and need to be revised. Likewise, data related to the development of germ cells and the features of the male reproductive system, including sperm, will contribute to understanding the biological mechanisms of reproduction and the systematics of its representatives. Aiming to provide these data, we describe the morphology of the male reproductive system and spermatozoa of Leptoglossus zonatus using light and transmission electron microscopies, respectively. Each of the two testes is surrounded by a bright red-pigmented sheath and formed by seven follicles arranged side by side. The two vasa deferentia are filled with individualized sperm, especially in their final portion, which is dilated and curved. After dilation, the vasa deferentia receive the ducts of the accessory glands of mesodermal origin. The other unpaired accessory gland is of ectodermal origin and opens into the ejaculatory duct. Both glandular types are densely coiled and have lumens filled with secreted material. Testicular follicles contain cysts with germ cells at different stages of spermatogenesis, indicating continuous production of gametes throughout adult life. Mature sperm measure around 310 μm long, with a nucleus of 36 μm and a flagellum formed only by an axoneme of 9 + 9 + 2 microtubules and two symmetrical mitochondrial derivatives. Like the sperm of other Heteroptera, the acrosome has a single structure (without perforatorium), there are no accessory bodies in the flagella, and the mitochondrial derivatives are connected to the axonemes, supporting the synapomorphic condition of these characteristics for this suborder of bedbugs. RESEARCH HIGHLIGHTS: The Leptoglossus zonatus sperm are slender and long, about 310 μm in length, and a nucleus 36 μm long. Spermatogenesis occurs throughout adult life and equally in the seven testicular follicles. The centriole adjunct in L. zonatus sperm does not give rise to accessory bodies. The ectodermal gland produces a filamentous secretion, whereas in the ectodermal sac, the secretion is globular., (© 2024 Wiley Periodicals LLC.)

Sexually selected weapons, such as the antlers of deer, claws of crabs, and tusks of beaked whales, are strikingly diverse across taxa and even within groups of closely related species. Phylogenetic comparative studies have typically taken a simplified approach to investigate the evolution of weapon diversity, examining the gains and losses of entire weapons, major shifts in size or type, or changes in location. Less understood is how individual weapon components evolve and assemble into a complete weapon. We addressed this question by examining weapon evolution in the diverse, multi-component hind-leg and body weapons of leaf-footed bugs, superfamily Coreoidea (Hemiptera: Heteroptera). Male leaf-footed bugs use their morphological weapons to fight for access to mating territories. We used a large multilocus dataset comprised of ultraconserved element loci for 248 species and inferred evolutionary transitions among component states using ancestral state estimation. Our results suggest that weapons added components over time with some evidence of a cyclical evolutionary pattern-gains of components followed by losses and then gains again. Furthermore, our best estimate indicated that certain trait combinations evolved repeatedly across the phylogeny, suggesting that they function together in battle or that they are genetically correlated. This work reveals the remarkable and dynamic evolution of weapon form in the leaf-footed bugs and provides insights into weapon assembly and disassembly over evolutionary time., (© The Author(s) 2024. Published by Oxford University Press on behalf of The Society for the Study of Evolution (SSE).)

Theory predicts that traits with heightened condition dependence, such as sexually selected traits, should be affected by inbreeding to a greater degree than other traits. The presence of environmental stress may compound the negative consequences of inbreeding depression. In this study, we examined inbreeding depression across multiple traits and whether it increased with a known form of environmental stress. We conducted our experiment using both sexes of the sexually dimorphic leaf-footed cactus bug, Narnia femorata (Hemiptera: Coreidae). Adult male cactus bugs have enlarged hind legs used as weapons in male-male contests; these traits, and their homologue in females, have been previously found to exhibit high condition dependence. In this study, we employed a small developmental group size as an environmental stress challenge. Nymph N. femorata aggregate throughout their juvenile stages, and previous work has shown the negative effects of small group size on survivorship and body size. We found evidence of inbreeding depression for survival and seven of the eight morphological traits measured in both sexes. Inbreeding depression was higher for the size of the male weapon and the female homolog. Additionally, small developmental group size negatively affected survival to adulthood. However, small group size did not magnify the effects of inbreeding on morphological traits. These findings support the hypothesis that traits with heightened condition dependence exhibit higher levels of inbreeding depression., (© The Author(s) 2023. Published by Oxford University Press on behalf of the European Society of Evolutionary Biology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

The fauna of Micronectidae (pygmy water boatmen) was investigated in Guilan Province. The present study has raised the number of micronectid species known from Iran to nine by reporting four first records for the country, including Micronecta carpatica Wrblewski, 1958, M. griseola Horvth, 1899, M. poweri (Douglas & Scott, 1869), and M. pusilla (Horvth, 1895). Morphological diagnoses for these four species are provided, accompanied by illustrations of male habitus, male genitalia, and a key to the species of Micronecta known from Iran.

The Ambrysus signoreti Stål species complex was recently diagnosed and subdivided into three sections based on morphology of the female subgenital plate. In the present study, the species in the second section, characterized by the posterior margin of the subgenital plate with central lobe extending posteriorly further than the posterolateral corners, are revised. Supplemental descriptions for four species described by La Rivers and Usinger are provided. The group includes six species: four from Mexico (Ambrysus brailovskyi Reynoso & Sites, A. henryi Reynoso & Sites, A. inflatus La Rivers, A. lundbladi Usinger), one from Mexico and the United States (A. lunatus Usinger), and one from Costa Rica (A. harmodius La Rivers). Also, the subspecies A. lunatus menoides La Rivers is proposed as a junior synonym of A. lundbladi. We herein report for the first time characteristics of the previously unknown male of A. lundbladi. Additionally, we present new state records from Mexico for A. inflatus and A. lundbladi, and new province records from Costa Rica for A. harmodius. Finally, an illustrated key to the species in the second section of the complex is provided.

In the present study, new distribution records and notes on the wing polymorphism of Limnocoris pallescens (Stål, 1861), a species distributed in Colombia and Venezuela, are presented. Also, after the discovery of two female paralectotypes of L. pectoralis Montandon, 1897 deposited at the Natural History Museum in London, ongoing uncertainty about the shape of the diagnostic mediosternite VII (subgenital plate) of this species has been resolved.

Interommatidial sensilla have been explored for their taxonomic value and other aspects in Diptera and Lepidoptera. In Heteroptera, Eurystethus is the only genus where these structures were examined in delimiting subgenera and species. This study investigates the presence, distribution, and morphology of interommatidial sensilla in Discocephalinae species and discusses the sensilla's value for cladistic and taxonomic appraisals. Twenty species of 18 genera were analyzed: 16 Discocephalini genera, one genus in Ochlerini, and one genus in Edessinae. Species' heads were observed from photographs taken with light microscopy (LM) and scanning electron microscopy (SEM). From these images, we identified eleven types of sensilla, classified into chaetica, trichoidea and coeloconica. In LM, only sensilla chaetica with a length of 40-100 μm were visible, present in six species. Under the SEM at least one type of sensillum was visible in 19 of the 20 species analyzed. No difference between the various kinds of sensilla were apparent between males and females or adults and nymphs of a given species. Both subgenera of Eurysthetus have the same type of sensillum (chaeticum type I), which suggests this is not a delimiting feature. We conclude that sensilla chaetica can be a valuable character to delimit groups of genera within Discocephalini., Competing Interests: Declaration of competing interest None., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Two new species of the leucophoropterine plant bug genus Sejanus Distant are described, namely S. epicurus n. sp. (Pingtung, Taiwan) and S. ryujin n. sp. (Nagasaki, Japan). Both species were recently confirmed to be associated cryptically with the bracts and flower buds of Hibiscus spp. (Malvaceae). An updated key is provided to aid in identification of the Japanese and Taiwanese congeners.

The species-rich Ambrysus signoreti Stål species complex is diagnosed and subdivided into three sections based on morphology of the female subgenital plate. The species in the first section, characterized by the posterior margin of the subgenital plate with posterolateral corners extending posteriorly further than the central lobe, are revised. The group includes four species: two previously described from Mexico (Ambrysus cosmius La Rivers, A. schuhi Reynoso & Sites), one from Costa Rica (A. variegatus Usinger), and a new species, A. morelosensis n. sp., from central Mexico. The description of the new species and transfer of A. mormon Montandon to the A. guttatipennis Stål species complex brings the total number of species in the complex to 24 and the total number of described species of Ambrysus to 68. Also, an illustrated key to the species in this first section of the complex is provided. Finally, we present new state records from Mexico for A. cosmius and new province records from Costa Rica for A. variegatus.

The flat bugs, Aradidae, have exceptionally long piercing-sucking stylets coiled up at rest in the anterior part of the head. Previous studies suggested that the majority of aradids can be divided into two groups by the direction of stylet coiling, clockwise or anticlockwise. Detailed reconstruction of the head skeleton and musculature from series of polished sections, examined in SEM, of epon-embedded specimens of three species has shown that these groups represent two disparate modifications of the head groundplan. In Aradus betulae (L.), the stylet coil is accommodated inside the greatly enlarged anteclypeus within an expansible membranous diverticulum of its epipharyngeal cuticle. In contrast, in Isodermus planus Erichson and Carventus brachypterus Kormilev, the coil lies freely underneath the anteclypeus between the extended maxillary lobes (in I. planus fused with the extended gular lobe). The intraclypeal coils occur in the subfamilies Aradinae, Calisiinae, and Chinamyersiinae and the subclypeal coils in Isoderminae, Carventinae, Mezirinae, Aneurinae, Prosympiestinae, and possibly in the closely related family Termitaphididae. Each method of stylet coiling is associated with a suite of divergently specialized structural traits, suggesting that the two groups have independently evolved from ancestors endowed with regular stylets. Functional mechanics of the coiled stylet bundles are discussed., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

A phylogenetic analysis of the subfamily Mirinae was conducted based on 89 external and genitalic morphological characters. Forty-six species belonging to 30 genera were coded and phylogenetic analysis reconstructed using un-weighted (EW) and implied weighted (IW) characters in a parsimony analysis. This resulted in the monophyly of eight genera including Stenodema, Polymerus, Orthops, Lygus, Phytocoris, Adelphocoris, Grypocoris and Brachycoleus, the ACM (Adelphocoris, Creontiades, Megacoelum) complex, Closterotomus, Calocoris and Lygus complexes. The phylogenetic relationships and supporting morphological characters are discussed. The taxonomic status of Pseudomegacoelum irbilanum was evaluated. Scanning electron micrographs, drawings of genitalic structures, digital images of the habitus of selected species are presented to illustrate characteristic features. This study is the first attempt to analyze the phylogenetic relationship of plant bugs in Iran.

The riffle bugs of the Rhagovelia angustipes complex have presented problems in taxonomy due to high intra-specific variability. Here we identified variation in the complex with morphometric techniques. We analyzed variation of the characters and performed a phylogenetic analysis of a combined matrix of linear measurements, geometric configurations, and discrete characters. We found that characters such as head length, metanotum length, femur width, and the evaluated shape of four characters (head, abdomen, fore tibia, hind femur) were important for the delimitation of species. In particular, we identified the metanotum length as a character that had not been previously considered in the taxonomy of the complex. The phylogenetic reconstruction allowed us to recover some relationships established for the taxonomy of the complex for the salina group, except for the species R. colombiana that was closer to R. calceola and R. calopa. This may be due to a similar natural history, since they share areas of distribution, while the R. bisignata and R. hambletoni groups could not be recovered, showing their low morphological support. In general, the geometric morphometric characters showed high levels of homology, with the head and the anterior tibia being the ones that had the best performance in the tree. Finally, the use of morphometric tools proved to be a powerful input for the taxonomic resolution of species complexes that have problems in their delimitation., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

The new species Paravelia ameliae (Heteroptera: Veliidae) is described based on macropterous specimens from the Department of Putumayo, in the Amazonian region of Colombia. The new species can be distinguished from all congeners mainly by the bicolored pronotum (dark-brown on the anterior two-thirds and light-brown posteriorly); the absence of distinct pruinosity or silvery patches on the anterior lobe of the pronotum; the basal macula of the forewing small and roughly ovate; the grasping comb of the male fore tibia occupying more than half of its length; the male hind femur with a row of 15 spines on the basal two-thirds; and the male paramere notched basally on its dorsal surface. Furthermore, this species displays sexual dimorphism in body shape and in hind tibial length, with males having a slightly constricted mid-abdominal region and hind tibia distinctly longer than in females. Also, in order to describe external morphological characteristics not mentioned in previous studies, supplemental descriptions are provided for P. albotrimaculata (Kirkaldy, 1899), P. loutoni Polhemus, 2014, P. nieseri Moreira Barbosa, 2012, and P. rotundanotata (Hungerford, 1930). Illustrations and a distribution map of all species treated here are presented.

A new species, Meschia brevirostris sp. nov. (Hemiptera: Heteroptera: Lygaeoidea: Meschiidae), is described from New Caledonia. Photographs and SEM micrographs of the male and female habitus, genital structures and selected morphological structures are presented.

A new species, Kohnometopus yasunagai sp. nov. (Hemiptera, Heteroptera, Miridae, Isometopinae, Gigantometopini), is described from Peninsular Malaysia. Habitus and SEM images of the holotype female and necessary morphological structures are presented. The structure of the female abdomen including the genitalia are also shown in detail. A key to all known Kohnometopus species is provided.

The Asopinae are known for their predatory behavior, differing from the phytophagous habits of most pentatomoids, feeding mostly on soft body insects such as larvae of Lepidoptera and Coleoptera. For this reason, asopines have been studied as biological controllers in integrated pest management programs. Notwithstanding their clear relevance, the general knowledge about Asopinae has important gaps, especially regarding immature. Thus, the importance of studying eggs and nymphs of true bugs (Heteroptera) is evident, contributing to understand their classification, biology, and evolution. In this perspective, we conducted a research about immature of predatory stink bugs, highlighting critical features for identification. We present: (1) a literature overview about eggs and nymphs of predatory stink bugs guided by selected categories; (2) images of females laying eggs of ten species and nymphs of thirty-four species, obtained on websites with a citizen science approach; (3) a comparative morphology of immature of six species reared under laboratory conditions, which we examined using light and scanning electron microscopy. We found a remarkable morphological diversity of both eggs and nymphs of Asopinae, revealing key features to establish diagnoses for identification and potential characters to phylogenetics, such as the aero-micropylar processes and chorion scultpturing of the eggs; and the coloration, labium and abdominal plates morphology of nymphs. The results show that little is known about Asopinae immature considering the diversity of the group; however, information obtained by citizen science initiatives, for instance, can improve this knowledge., (Copyright © 2021 Elsevier GmbH. All rights reserved.)

Access to hitherto unexploited ecological opportunities is associated with phenotypic evolution and often results in significant lineage diversification. Yet our understanding of the mechanisms underlying such adaptive traits remains limited. Water striders have been able to exploit the water-air interface, primarily facilitated by changes in the density of hydrophobic bristles and a significant increase in leg length. These two traits are functionally correlated and are both necessary for generating efficient locomotion on the water surface. Whether bristle density and leg length have any cellular or developmental genetic mechanisms in common is unknown. Here, we combine comparative genomics and transcriptomics with functional RNA interference assays to examine the developmental genetic and cellular mechanisms underlying the patterning of the bristles and the legs in Gerris buenoi and Mesovelia mulsanti , two species of water striders. We found that two duplication events in the genes beadex and taxi led to a functional expansion of the paralogs, which affected bristle density and leg length. We also identified genes for which no function in bristle development has been previously described in other insects. Interestingly, most of these genes play a dual role in regulating bristle development and leg length. In addition, these genes play a role in regulating cell division. This result suggests that cell division may be a common mechanism through which these genes can simultaneously regulate leg length and bristle density. We propose that pleiotropy, through which gene function affects the development of multiple traits, may play a prominent role in facilitating access to unexploited ecological opportunities and species diversification., Competing Interests: The authors declare no competing interest.

Males in many species engage in physical combat over access to mates, and sexual selection has led to the evolution of weapons to enhance contest performance. The size of these often-elaborate structures is known to be exquisitely sensitive to nutrition. However, we know very little about the degree to which nutrition affects other attributes of animal weapons that can be crucial to fighting. In this study, we investigated the impact of natural dietary variation on weapon structural integrity in a fighting insect, Narnia femorata (Hemiptera: Coreidae). Males in this species display their enlarged, spiny hind legs to other males, and these legs serve as weapons in aggressive physical contests where they are used to strike and squeeze opponents. N. femorata feeds on the fruit of prickly pear cactus and sets up territories on this plant. In North Central Florida the prickly pear Opuntia mesacantha ssp. lata blooms and begins to produce fruits in April and May. N. femorata has multiple, overlapping generations while the green fruits slowly ripen over the next several months. We examined insects reaching adulthood at two nearby time points in this range, June and July, to test the influence of the nutrition provided by ripening green cactus fruit on weapon size and its ability to resist puncture. We also raised insects on cactus with red, ripe fruit for comparison. We found a striking effect of cactus fruit phenology on weapons. Insects raised with the more mature green fruit (those in the second cohort) had 71% larger weapon area and 4.4 times greater puncture resistance than those raised on the early green fruit (those in the first cohort). In contrast, insects raised on red, ripe fruit were moderate in size, had high puncture resistance, and they changed little phenotypically from the first to second cohort. Increased structural integrity of the hind femur weapon was associated with the increased body size that came with better nutrition. This pattern highlights that cuticle thickness increased or its material properties changed when weapons were larger. Importantly, effects of nutrition on puncture resistance also transcended size. Insects of the same size had greater structural integrity if they received superior nutrition. Sexually selected weapons are often used as visual signals to conspecifics before fights, and this work hints that the size of the weapons may be a poor signal of weapon performance when nutrition is variable., (© The Author(s) 2021. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology.)

The family Pleidae is represented in Australia only by members of the genus Paraplea. Paraplea brunni (Kirkaldy, 1898) has a widespread distribution in Australia and is also known from New Guinea. Paraplea halei (Lundblad, 1933) appears to be an endemic species occurring only in the southeastern part of Australia. The widespread species P. liturata (Fieber, 1844) occurs in Australia but only in the Northern Territory and Western Australia. The description of P. bifurcata n. sp. documents a fourth pleid species, being known only from the Northern Territory. Paraplea bifurcata n. sp. is easily differentiated from other species of Paraplea by having a bifurcated abdominal keel. An identification key and discussion of morphological characters of the four species of Paraplea from Australia is given.

The taxonomic revision of 'Hypatropis complex', composed by Amauromelpia Fernandes Grazia, Hypatropis Bergroth, Luridocimex Grazia, Fernandes Schwertner, Stysiana Grazia, Fernandes Schwertner, and Pedinonotus Fernandes Grazia, updating the genitalic terminology, are presented here. The differential diagnosis of 'Hypatropis complex' and all of its members are provided. Photographs of the type-specimens and genitalia, species distributional map with new records, and a key to genera and species are also provided.

The new genus Megalofaciatus gen. nov. represented by two new species M. foliotibialis Taszakowski, Kim Herczek sp. nov. (the type species) and M. gibbosus sp. nov. Taszakowski, Kim Herczek (Hemiptera, Heteroptera, Miridae, Isometopinae, Gigantometopini), is described from Brunei. Photographs of the adult males and genital structures, as well as detailed SEM micrographs, are presented. The first finding of the largely modified leg in Gigantometopini is also reported.

Two new species of Tingidae are described from Panama: Acanthotingis deltoides sp. nov. and Stephanitis joceliae sp. nov. Descriptions and diagnosis for both Acanthotingis Monte and Stephanitis Stål are provided, and a key is given for the separation of the two known species of Acanthotingis. This is the first record of both genera from Panama. A checklist of all Neotropical species of both genera is presented.

In this paper, we present new data on the genus Macrosaldula Leston Southwood, 1964 based on material held in the collections of the National Museum (Prague, Czech Republic) and the Zoological Institute of the Russian Academy of Sciences (St. Petersburg, Russia). Macrosaldula graziae sp. nov., from South Uzbekistan and Tajikistan, is described. Among the Central Asian species of the genus, it is close to M. tadzhika (Kiritshenko, 1912) by the presence of long erect setae on the body dorsum, but the latter species differs in the smaller body size, the presence of light spots on the corium, and in the structure of the male genitalia. In extremely dark specimens of M. jakowleffi (Reuter, 1891), the hemelytra are opaque, with short erect setae. Siberian M. rivularia (J. Sahlberg, 1878), M. simulans Cobben, 1985 and the Far Eastern M. koreana (Kiritshenko, 1912) and M. violacea Cobben, 1985 are distinguished from the new species by the short pubescence on the dorsum. We provide new distributional data for M. clavalis Cobben, 1985 (Georgia), M. jakowleffi (Reuter, 1891) (China: Xinjiang: Altai Mts.-first record), M. miyamotoi Cobben, 1985 (Japan: Honshu), M. nivalis (Lindberg, 1935) (Afghanistan-first record, Kyrgyzstan, Tajikistan), M. scotica (Curtis, 1835) (Georgia: Adzharia; Russia: Murmansk District), and M. tadzhika (Afghanistan-first record, Tajikistan, Uzbekistan). The record of M. scotica from Uzbekistan is disconsidered, and the two specimens are referred to M. graziae sp. nov.

The new Neotropical hyaliodine Colimacoris joceliae Kim Jung, sp. nov., is described from Panama. Morphological information, including a description and diagnosis of the new species is presented with photographs. A key for the identification of the species of Colimacoris is also provided.

Hypsipyrgias joseliae sp. n. (Heteroptera: Tingidae: Tinginae) from New Guinea is described, illustrated and compared with its two relatives, namely H. telamonides Kirkaldy, 1908 from Australia, and H. euphues Drake and Ruhoff, 1962 from Lord Howe Island. Key to species of the genus Hypsipyrgias is also provided. Two genera very closely related to Hypsipyrgias Kirkaldy, 1908, namely Hypsotingis Drake, 1960 and Diplocysta Horváth, 1925 are re-diagnosed. Diplocysta globuliformis Hacker, 1928, D. papuana Drake, 1960, D. rustica, Drake, 1960 and D. thaleia Drake and Ruhoff, 1965 are transferred from Diplocysta to Hypsotingis.

The minute litter bugs (Heteroptera: Schizopteridae) fauna from the Brazilian Amazon comprises only nine species described during the past four years. In this paper, the Schizopteridae fauna of an Amazonian savanna was surveyed, resulting in the discovery of two new species of Corixidea Reuter and a new species of Schizoptera (Cantharocoris) McAtee Malloch: Corixidea graziae sp. nov., Corixidea quilombola sp. nov., and Schizoptera (Cantharocoris) savannensis sp. nov. The species C. graziae sp. nov. and C. quilombola sp. nov. can be distinguished from other Corixidea species by the shape of the process of mediotergite 8 while S. (Cantharocoris) savannensis sp. nov. can be recognized among species of its subgenus by a combination of the shape of the subgenital plate and right conjunctival appendage. The species herein described represent the first records of these genera for the Brazilian Amazon. We provide diagnoses, photographs of habitus, and illustrations of male genitalia.

Microvelia joceliae Magalhães Moreira, sp. nov. is described and illustrated based on material from Parque Natural Municipal das Andorinhas, Minas Gerais State, in southeastern Brazil. The new species can be distinguished from congeners occurring in the region by the pronotum of the apterous form covering almost the entire thorax dorsally, proepisternum with black denticles, male abdominal segments V-VII ventrally depressed, shape of the asymmetrical parameres, and female abdominal laterotergites reflected over the mediotergites and almost touching over segments V-VII.

The new genus Graziaphylus is described to include two new species, Graziaphylus joceliae and G. nigripes. This new taxon is part of a large suite of Heteroptera from Australia known to feed on species of Eremophila (Scrophulariaceae), including other members of the Miridae as well as the Tingidae. The appearance of Graziaphylus spp. is similar to that of Xiphoidellus Weirauch and Schuh from Australia, and to Chlamydatus Fieber from the Northern Hemisphere (among other genera), but with scalelike setae, and elongate pulvilli adnate over most of the claw length, and the distinctive structure of the male genitalia.

The fauna of semiaquatic bugs (Insecta: Hemiptera: Heteroptera: Gerromorpha) from Panama has been explored mainly between the end of the 19th century and the first half of the 20th century, with few reports since then, whereas that from Colombia has been intensively studied in the last decade. Here, we describe Rhagovelia joceliae Rodrigues Moreira, sp. nov. (Veliidae: Rhagoveliinae), from Panama. Additionally, new records from these countries are presented for Mesovelia mulsanti White, 1879, Mes. zeteki Harris Drake, 1941 (Mesoveliidae: Mesoveliinae), Lipogomphus leucostictus (Champion, 1898) (Hebridae: Hebrinae), Hydrometra caraiba Guérin-Méneville, 1857 (Hydrometridae: Hydrometrinae), Platyvelia brachialis (Stål, 1860), Stridulivelia (Stridulivelia) raspa (Hungerford, 1929) (Veliidae: Veliinae), R. elegans Uhler, 1894, R. perija Polhemus, 1997, R. rosensis Padilla-Gil, 2011 (Veliidae: Rhagoveliinae), Euvelia advena Drake, 1957, Microvelia albonotata Champion, 1898, Mi. fantastika Padilla-Gil, 2019, Mi. mimula White, 1879 (Veliidae: Microveliinae), Metrobates laudatus Drake Harris, 1937, Telmatometra ujhelyii Esaki, 1926 (Gerridae: Trepobatinae), Brachymetra albinervus (Amyot Serville, 1843) (Gerridae: Charmatometrinae), Potamobates anchicaya Polhemus Polhemus, 1995 (Gerridae: Cylindrostethinae), Limnogonus hyalinus (Fabricius, 1803), and Tachygerris opacus (Champion, 1898) (Gerridae: Gerrinae).

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.

Water striders of the genus Rhagovelia Mayr, 1865 (Insecta: Hemiptera: Veliidae) have colonized the water surface mainly in lotic freshwater systems, but also in coastal marine environments. They are characterized by the swimming fan in the distal tarsomere of the middle leg that allows them to quickly maneuver. In the Americas, it was subdivided into four monophyletic complexes (angustipes, collaris, obesa and robusta), one paraphyletic grade (abrupta), each with several groups of species, and one additional group (varipes). However, the taxonomy of this genus still has inconsistencies due to its morphological complexity and to the misinterpretation of characters. For this reason, we present a revision of the species of the angustipes complex occurring in Colombia. Material deposited in nine biological collections was examined, including several types. A total of 3,674 specimens  were studied, belonging to 26 valid species, of which R. boyacensis sp. nov., R. graziae sp. nov. and R. molanoi sp. nov., are described as new; and R. angustipes Uhler, 1894 is recorded from the country for the first time. Furthermore, eleven species are redescribed and twelve are considered synonyms. Finally, a key to the species of the angustipes complex occurring in Colombia is presented, as well as updated distribution maps.

The genus Belostoma comprises about 70 species classified in sixteen species groups. Here, the remarkable Belostoma triangulum group sensu Lauck, 1964, is revised. Belostoma bicavum Lauck, 1964 is proposed as a junior synonym of B. bachmanni De Carlo, 1957, which is added to this group. Thus, the rearranged group is now composed of two species: Belostoma bachmanni and B. triangulum Lauck, 1964. Redescriptions of these species are presented including a discussion about comparative morphology with other species of the genus. The geographic distributions of the species in the B. triangulum group are also updated.

A second species of the previously monotypic plant bug genus Campyloneura, C. joceliae sp. nov. is described based on specimens from Nkolbisson, Cameroon. A key, differential diagnoses, digital habitus images, illustrations of male and female genitalic structures, and scanning micrographs of diagnostic morphological structures are provided for the new species and C. virgula (Herrich-Schaeffer, 1835).

The genus Cryphocricos Signoret, 1850 was recently determined in a molecular phylogeny to be distantly related to other taxa of the subfamily Cryphocricinae to the extent that it is now once again the sole member of the subfamily. This exclusively New World group of aquatic bugs lives in fast and usually turbulent current and respires by means of a plastron. Efforts to identify morphological features to distinguish among the species have largely fallen short, and some species have been established based on features that exhibit a high degree of intraspecific variation overlapping those of other species. Presented here is a review of the 13 described species with discussions of their features and photos of type specimens, and three new species from Venezuela and Colombia are described. Also presented is a diagnostic attribute unique to the enigmatic Cryphocricos barozzii Signoret, 1850.

Two new species of Ocyochterus are described, O. graziae from Ecuador, and O. gilloglyi from Panama, and compared to the other two Andean species previously known in the genus. Dorsal habitus and anterior head photos are provided for all described species of Ocyochterus, and photomicrographs are provided for the male genitalic structures of O. graziae and O. gilloglyi. A distribution map is provided for all species in the genus.

Eocanthecona furcellata Wolff (Hemiptera: Pentatomidae) is a native generalist predator which attacks and kills its prey by first inserting its stylet into the prey's body and then injecting saliva into it. Here, we describe the histology and ultrastructure of its salivary glands. The study showed that the salivary glands were made up of pairs of principal and tubular accessory salivary glands. The principal salivary glands were bilobed and consisted of a smaller anterior lobe and a larger elongated posterior lobe. The ducts of the principal and accessory salivary glands were located in a narrow region between the anterior and posterior lobe known as the hilum. The principal salivary gland was lined with a single-layered epithelium. The cells cytoplasm was enriched with rough endoplasmic reticulum and secretory, and the nucleus showed a higher level of uncondensed chromatin. The basal region of the cell had plasma membrane infoldings. The cytoplasm of the accessory gland was rich in rough endoplasmic reticulum and many large cavities. The ducts of the principal salivary gland were made up of a single layer of flattened cells which had a thin cuticle lining the apical portion. Variation in the lumen content of the different lobes, which made up the principal gland suggested that their chemical products also varied. These results indicate that these two salivary glands produce the proteins found in the saliva., (© 2020 Wiley Periodicals LLC.)

The coevolution between sperm length and size of the female sperm-storage organs is described for the first time within Heteroptera. The long sperm of the measurer bug Hydrometra stagnorum is characterized by the unusually long acrosome with its anterior region helically arranged, and by a very short nucleus. The sperm flagellum has a 9 + 9+2 conventional axoneme and crystallized mitochondrial derivatives. The female spermatheca consists of an extraordinarily long spermathecal duct ending with an apical spermathecal bulb into which flows also the secretions of a relatively short spermathecal gland. Both spermathecal duct and gland have a thin epithelium lined by a cuticle, beneath which a complex of secretory and duct forming cells are present. The secretions of these two structures flow into the apical spermathecal bulb. A thick layer of muscle fibers surrounds the epithelium. These results confirm the opinion that the dimensions of the female reproductive sperm-storage organs are able to drive the sperm morphology., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

A pair of ventral cephalic trichobothria was observed for the first time and so far the only one in a representative of single species of Miridae (Fulvius carayoni) in 2013. The purpose of our research was to verify the hypothesis that this is not an exception, but a characteristic feature of all plant bugs. Twenty-three representatives of all seven subfamilies of Miridae were examined using a scanning electron microscope. The results presents detailed data on the distribution and ultramorphology of the cephalic trichobothria in plant bugs. A pair of ventral cephalic trichobothria was observed in all of the examined species. Each trichobothrium of this pair is located laterally to the first article of the rostrum, on the gula (between the buccula and the antennal tubercle). Moreover, a pair of dorsal cephalic trichobothria was observed for the first time. They were found in nine species, located above the antennal tubercle, towards the center of the frons., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Spiracles are the openings in the exoskeleton of insects through which air enters into the respiratory system that is formed by a series of tubes called tracheae. They are primarily located on the abdomen, but can also occur on the thorax, including the metathorax. An insect metathoracic spiracle is usually composed of an external opening and a more internal filter apparatus. We propose new terminology for these structures, and we explore the value in their use in taxonomic and phylogenetic studies within the true bug infraorder Pentatomomorpha, with emphasis on the superfamily Lygaeoidea (Insecta: Hemiptera: Heteroptera). These structures were studied using scanning electron microscopy. Two types of metathoracic spiracle external openings were recognized: a narrow opening (type N), which is slit-like; and a wide opening (type W), with internal fine structures located between the mesothoracic and metathoracic margins of the interpleural suture clearly visible. The filter apparatus in the Pentatomomorpha consists of modified mushroom bodies of the metathoracic scent gland evaporatorium, for which the term mycoid filter processes is proposed. Eight different types of mycoid filter processes, and an unmodified microsculpture type (a type with usual cuticular microsculpture) and filter setae can be found on the anterior or posterior margins of the metathoracic spiracle. We believe the wide opening (type W) to be the plesiomorphic character state in the Pentatomomorpha, with multiple, independent transformations leading to the narrow opening in Lygaeoidea. Considerable variability in the structure of the spiracle opening (in Lygaeoidea), and in the structure of the mycoid filter processes (in Pentatomomorpha) was detected. Overall, we found the morphology of these structures to be of limited value concerning the taxonomy or for determining phylogenetic relationships of the higher taxa (families) of Pentatomomorpha, but they may be useful as additional evidence for taxonomic and phylogenetic studies at the generic and perhaps the tribal levels., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Cold winter temperatures can influence insects' survival in temperate zones. Brown marmorated stink bug, Halyomorpha halys (Stål) overwinters as adults in natural and human-made structures. In this study, we characterized low temperature mortality rates of H. halys adults that were either entering (ENA) or exiting (EXA) overwintering microhabitats. We considered the effect of different duration of cold exposure on mortality. We determined the impact of insect nutritional status and weight on cold tolerance. We additionally evaluated the effects of cold exposure on H. halys adult longevity and fecundity. Mortality of ENA and EXA adults was determined for 6 h and 2 h periods at - 2.5 °C and 2.5 °C respectively. EXA adults displayed higher mortality rates compared to ENA individuals at the low-temperature regimes. Halyomorpha halys adult survival rate was higher when their nutrient index (EXA individuals only) and weight were high. Low-temperature exposure increased longevity, but reduced fecundity of ENA females. The data further highlight how extreme spring frost events can result in significantly increased mortality levels of H. halys adults.

Parameres are male genital structures found in many insects which are often used as clasping devices to exert dominance in copula. The asopines have evolved a remarkable additional pair of similar structures, often denominated processes, which combines with the parameres in a tweezers-like system. Processes in similar positions have also been found in other subfamilies of Pentatomidae, but smaller and less developed. Using scanning electron microscopy, we document the among-species variability found in the clasping structures in asopines. We first revealed a vast diversity of ornamentations, such as sensilla and microsculpture. When present, these ornamentations are invariably found on both, the parameres and processes, and often on the corresponding female parts, the valvifers VIII, indicating a functional role of attachment and sensory perception in copula for the ornamentations. We also show that the processes are drastically different between the Asopinae and non-asopines. Therefore, we suggest the term "pseudoclasper" for the Asopinae processes and "superior process of dorsal rim" for the remaining examined taxa. The pseudoclaspers are directly connected to and attached in the same place as the parameres in asopines, while the superior processes of dorsal rim and parameres are completely disconnected in other pentatomids. These results indicate a non-homologous origin between pseudoclaspers and superior processes of dorsal rim in Pentatomidae., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Heteropterans communicate chemically through thoracic or abdominal glandular complexes. The dorso-abdominal scent glands (DAGs) are externalized by cuticular specialized structures forming the external scent efferent system (SES). Different groups in Heteroptera present other glands, such as the Asopinae (Pentatomidae), whose males can have ventral abdominal pheromonal glands externalized by cuticular modifications, called glandular patches (GPs). Here we describe the SES of DAGs and, for the first time, the GPs of 22 Asopinae genera. The ostioles of SES 1 vary in shape. SES 2 and SES 3 were restricted to scars, indicating that only the SES 1 remains functional in adults. The GPs are found mostly in segments V and VI. We have not found any difference in the morphological pattern between the SES of species bearing GPs and those lacking it, meaning that the acquisition of GPs is likely related to some sexual behavior, thus not as a complex structure replacing any role of the DAGs. The cuticle of the GPs is microsculptured, bearing many pores surrounding the base of sensilla being the pathway for the secretions to reach the outside of the exoskeleton. The sensilla may be adaptations to increase the contact surface, assisting rapid evaporation of the volatile secretions from the pores., (Copyright © 2020 Elsevier Ltd. All rights reserved.)