Morphology of the male reproductive system and sperm of Leptoglossus zonatus (Dallas, 1852) (Heteroptera: Coreidae).

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.

Sperm morphology of Tingidae Laporte, 1833 (Miroidea: Cimicomorpha).

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.

The evolution of multi-component weapons in the superfamily of leaf-footed bugs.

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.

Inbreeding depression in a sexually selected weapon and the homologue in females.

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.

Revision of the Ambrysus signoreti Stål species complex (Heteroptera: Naucoridae: Ambrysinae). Section 2.

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.

Notes on the morphology of two species of Limnocoris Stål (Heteroptera: Naucoridae) from South America.

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.

Morphology of interommatidial sensilla of Discocephalini (Heteroptera: Pentatomidae: Discocephalinae).

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.

The Micronecta Kirkaldy, 1897 (Hemiptera: Heteroptera: Micronectidae) of Iran, with four new records and an illustrated key to the species.

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 mouthparts of the Aradidae (Insecta: Hemiptera: Heteroptera).

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.

New species and notes on Paravelia Breddin, 1898 (Heteroptera: Veliidae) from South America.

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.

Meschia brevirostris sp. nov., from New Caledonia (Hemiptera: Heteroptera: Lygaeoidea: Meschiidae).

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.

Kohnometopus yasunagai sp. nov., (Hemiptera, Heteroptera, Miridae, Isometopinae) from Peninsular Malaysia.

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.

Morphometric tools to solve species complexes: The case of Rhagovelia angustipes (Hemiptera: Veliidae).

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.

The eggs and nymphs of predatory stink bugs (Hemiptera: Pentatomidae: Asopinae): what do we know?

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.

Leg length and bristle density, both necessary for water surface locomotion, are genetically correlated in water striders.

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.

Two new unique hibiscus-inhabiting species of the plant bug genus Sejanus Distant from Japan and Taiwan (Hemiptera: Heteroptera: Miridae: Phylinae).

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.

Revision of the Ambrysus signoreti Stål species complex (Heteroptera: Naucoridae: Ambrysinae). Section 1.

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.

A phylogenetic study of the relationships within Mirinae subfamily (Insecta: Heteroptera: Miridae) based on specimens from Northern Iran: Insight into analyses of genera complexes.

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.

Review of the Paraplea Esaki amp; China (Hemiptera: Heteroptera: Nepomorpha: Pleidae) of Australia, with description of a new species.

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.

A remarkable new genus and two new species of the Gigantometopini (Hemiptera, Heteroptera, Miridae, Isometopinae) from Brunei.

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.