Outside the pattern: Evolution of the genital asymmetry in Saicinae (Hemiptera: Heteroptera: Reduviidae).

Despite genital structures in insects being consistently important as systematic and taxonomy evidence, within assassin bugs (Heteroptera, Reduviidae) at least, the male and female genitalic structures of several subfamilies are poorly or totally unknown. The genital structure is mostly symmetric within Saicinae genera, but male genital asymmetry has been recorded in Gallobelgicus, Polytoxus, and recently Pseudosaica. The subfamily has been considered as closely related to Emesinae and Visayanocorinae but this hypothesis has never been tested using a comprehensive taxa sampling, being a constraint to test morphological traits changes or exploring characters' evolution hypotheses. Here, we compiled a morphological data set of 170 characters that includes external morphological characters and genitalia of both sexes of Saicinae which was analyzed cladistically including 55 terminals, comprising 16 genera (64% of the generic diversity), 43 species of Saicinae and 12 outgroups. Saicinae was recovered as polyphyletic, Saicireta correntina is recovered as sister-species of Empicoris armatus + Collartida (Emesinae), Oncerotrachelus, Carayonia (Visayanocorinae), and the Clade Saicinae sensu stricto. Carayonia orientalis is recovered as sister-species of Saicinae sensu stricto. Ancestral state reconstruction of symmetry of the male genitalia shows an ancestor with symmetric male genitalia, two independent emergences of asymmetrical male genitalia within Saicinae sensu stricto, and the asymmetrical endosomal sclerites appearing before the other asymmetric traits.

Biological, ecological, morphological and cytogenetic analyses, with taxonomic notes of emZelurus/em emochripennis/em (Stål, 1854) (Hemiptera: Heteroptera: Reduviidae: Reduviinae).

Based on specimens of Zelurus ochripennis (Stål, 1854) collected in the entrance zone of a small terrestrial cave, some biological, ecological, morphological and cytogenetic data, as well, as the general morphology of their nymphs are presented for the first time. A short taxonomic summary of the species is also provided.

A new species of emCosmoclopius/em Stål, 1866 from Argentina (Hemiptera, Reduviidae).

A new species of Cosmoclopius Stål, 1866, C. joceliae sp. nov. is described based on specimens collected in northern Argentina. This new species is recognized by the vertical and truncate median process of pygophore, and the short-recurved spine on the apex of the dorsal phallothecal sclerite; and other features such as the dorsally black head, pronotum, and femora, and the thoracic sterna black with median pale markings; some females show lighter posterior pronotal lobe and femora with more conspicuous dark and pale bands. Digital images of the adult male and female and male genitalia are provided, as well as a comparison with the species of the genus are given.

Proguithera caspersi/, a new cavernicolous thread-legged bug species (Hemiptera: Heteroptera: Reduviidae: Emesinae) from Hainan, China.

The thread-legged bug genus Proguithera Wygodzinsky, 1966 is recorded from China for the first time, and a new species, P. caspersi sp. nov., is described and illustrated. The new species is cavernicolous and was collected on the walls of a cave together with another emesine species Myiophanes tipulina Reuter, 1881. The type species of the genus, P. drescheri (Wygodzinsky, 1966), is re-diagnosed based on the examination of the holotype. An updated key to species of the Guithera-Lutevula genus group is provided.

The assassin bug Pristhesancus plagipennis produces two distinct venoms in separate gland lumens.

The assassin bug venom system plays diverse roles in prey capture, defence and extra-oral digestion, but it is poorly characterised, partly due to its anatomical complexity. Here we demonstrate that this complexity results from numerous adaptations that enable assassin bugs to modulate the composition of their venom in a context-dependent manner. Gland reconstructions from multimodal imaging reveal three distinct venom gland lumens: the anterior main gland (AMG); posterior main gland (PMG); and accessory gland (AG). Transcriptomic and proteomic experiments demonstrate that the AMG and PMG produce and accumulate distinct sets of venom proteins and peptides. PMG venom, which can be elicited by electrostimulation, potently paralyses and kills prey insects. In contrast, AMG venom elicited by harassment does not paralyse prey insects, suggesting a defensive role. Our data suggest that assassin bugs produce offensive and defensive venoms in anatomically distinct glands, an evolutionary adaptation that, to our knowledge, has not been described for any other venomous animal.

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

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

New synonymies among species of Nitornus (Hemiptera: Heteroptera: Reduviidae).

Based on examination of types and additional specimens, the following new synonymies are proposed in the genus Nitornus Stål, 1859 (Hemiptera: Heteroptera: Reduviidae: Stenopodainae): Nitornus lobulatus Stål, 1859 = Nitornus monrosi (Wygodzinsky, 1959), syn. nov. = Nitornus barberi Froeschner, 1999, syn. nov.; and Nitornus parkoi (Costa Lima & Campos Seabra, 1945) = Nitornus seabrai (Prosen & Martínez, 1958), syn. nov. These synonymies result in Nitornus having only two valid species. Comments on morphological variations and the male genitalia of the species studied here are provided.

A new species of Dohrnemesa from Brazil, with notes on the male of D. carvalhoi and on D. albuquerquei (Hemiptera: Heteroptera: Reduviidae: Emesinae).

Dohrnemesa oliveirai sp. nov. (Hemiptera: Heteroptera: Reduviidae: Emesinae: Emesini) is described from state of Pará, Brazil, based on a male specimen. The male genitalia of D. carvalhoi (Wygodzinsky, 1966) is described for the first time and some notes about D. albuquerquei (Wygodzinsky, 1966) are furnished.

The genus Zelurus Hahn, 1826, in Brazilian caves: description of new species and comments on the potential distribution of the genus in South America.

A survey on species of the genus Zelurus Hahn, 1826 (Reduviidae) occurring in Brazilian caves is provided. Zelurus tambejua sp. n. and Zelurus gerevatinga sp. n. collected from caves in Brazil are described. Comments about the current and potential distribution of the genus as a whole and of species of Zelurus found in caves for South America are also provided.

A revision of the Australian genus Trachylestes with the description of two new species (Hemiptera: Heteroptera: Reduviidae: Harpactorinae).

Two new species, Trachylestes barrowensis sp. nov. from Barrow Island, Western Australia and T. queenslandensis sp. nov. from southeastern Queensland are described, and a key for their separation from other known species of the Australian endemic genus Trachylestes Stål, 1868 (Hemiptera: Heteroptera: Reduviidae: Harpactorinae) is given.

Transfer of the assassin bug Nitornus fuliginosus to the genus Apronius (Hemiptera: Heteroptera: Reduviidae: Stenopodainae).

Based on examination of its lectotype (here designated), the assassin bug Nitornus fuliginosus Distant, 1902 (Hemiptera: Heteroptera: Reduviidae: Stenopodainae) is transferred to the genus Apronius Stål, 1865, with the resulting new combination: Apronius fuliginosus (Distant, 1902), comb. nov.

Origin, evolution and function of the hemipteran perimicrovillar membrane with emphasis on Reduviidae that transmit Chagas disease.

The peritrophic matrix is a chitin-protein structure that envelops the food bolus in the midgut of the majority of insects, but is absent in some groups which have, instead, an unusual extra-cellular lipoprotein membrane named the perimicrovillar membrane. The presence of the perimicrovillar membrane (PMM) allows these insects to exploit restricted ecological niches during all life stages. It is found only in some members of the superorder Paraneoptera and many of these species are of medical and economic importance. In this review we present an overview of the midgut and the digestive system of insects with an emphasis on the order Paraneoptera and differences found across phylogenetic groups. We discuss the importance of the PMM in Hemiptera and the apparent conservation of this structure among hemipteran groups, suggesting that the basic mechanism of PMM production is the same for different hemipteran species. We propose that the PMM is intimately involved in the interaction with parasites and as such should be a target for biological and chemical control of hemipteran insects of economic and medical importance.

Two new species of Phasmatocoris Breddin from Brazil, and description of the male of Phasmatocoris borgmeieri (Wygodzinsky) (Hemiptera: Heteroptera: Reduviidae: Emesinae).

Phasmatocoris catarinae sp. nov. and P. galvaoi sp. nov. (Hemiptera: Heteroptera: Reduviidae: Emesinae: Emesini) are described from Brazil based on female and male specimens. The male of Phasmatocoris borgmeieri (Wygodzinsky, 1945) is described and short taxonomical notes on this species and P. xavieri Gil-Santana et al., 2007 are provided.

The first fossil record of the Emesinae genus Emesopsis Uhler (Hemiptera: Heteroptera, Reduviidae) from Eocene Baltic amber.

Two new fossil representatives of the assassin bug family Reduviidae are described as new from Baltic amber (Upper Eocene), belonging to the genus Emesopsis of the tribe Ploiariolini (Emesinae): Emesopsis putshkovi sp. nov. and E. similis sp. nov. These representatives of the Emesinae are the oldest fossil bugs of the genus Emesopsis known so far, and reported for the first time. This genus is also briefly diagnosed.

A new species of the genus Sphedanolestes Stål 1866 (Hemiptera: Reduviidae: Harpactorinae) from China, with a key to Chinese species.

A new harpactorine bug, Sphedanolestes zhengi sp. nov., is described and illustrated based on specimens collected from southwestern China. A key to 17 Chinese species of the genus, including the new species, is provided. The bionomics of the new species is briefly noted.

Neotropical Physoderinae revisited, with description of a new, sexually dimorphic species of Leptophysoderes Weirauch (Hemiptera: Reduviidae).

The small reduviid subfamily Physoderinae has the greatest species diversity in the Oriental region and Madagascar. Only the two monotypic genera Cryptophysoderes Wygodzinsky and Maldonado and Leptophysoderes Weirauch are currently known from the Neotropical region. We here describe and document a new, sexually dimorphic species of Physoderinae, Leptophysoderes sarapiqui sp. nov. from Costa Rica. The generic diagnosis of Leptophysoderes is modified to accommodate the new species. Females and immatures of Leptophysoderes are documented for the first time.

Ultrastructure of the fossula spongiosa and pretarsus in Haematoloecha nigrorufa (Stål) (Hemiptera: Heteroptera: Reduviidae: Ectrichodinae).

The ultrastructure of the fossula spongiosa and pretarsus of adult Haematoloecha nigrorufa (Stål) (Heteroptera: Reduviidae: Ectrichodinae) was examined for the first time using scanning electron microscope. The fossula spongiosa of H. nigrorufa is located on the ventral surface of the distal part of the tibia of both the fore- and midlegs. The area of the fossula spongiosa on the female foreleg is approximately 251338.88 µm(2), while the area of the fossula spongiosa on the male foreleg is markedly smaller, only about 196548.98 µm(2). For both genders the area of the fossula spongiosa on the foreleg is approximately 1.50 times as large as that on the midleg. Externally, the ventral surface of the fossula spongiosa is covered by a large number of tenent hairs that are evenly interspersed with a few mechanosensory setae. Each tenent hair consists of two parts: a hair shaft and an apical plate. A tenent hair is 22.58 ± 1.60 µm in length, 1.90 ± 0.09 µm in shaft diameter, and 10.90 ± 0.63 µm(2) in apical plate area. Morphologically, the tenent hairs are similar and constitute a nearly uniform hair array on the ventral side of the fossula spongiosa. The density of tenent hairs is about 4.46 ± 0.35 hairs per 100 µm(2) and the total number of tenent hairs is more than ten thousand on the fossula spongiosa of the female foreleg. These tenent hairs are presumed to function as adherence during locomotion or prey capture of the assassin bugs. In addition, scanning micrographs and descriptions for the pretarsus are also given.

A taxonomic review of the polymorphic assassin bug genus Rihirbus Stål (Hemiptera: Reduviidae: Harpactorinae).

Two species in the genus Rihirbus Stål are recognized, redescribed and illustrated. The diagnosis of the genus is slightly modified. The deposition information of Miller's type specimens is corrected. Rihirbus trochantericus Stål is newly recorded from Cambodia, Laos, Nepal, Thailand, and Vietnam. A key for the identification of species of Rihirbus is provided. The sexual dimorphism and polymorphism of this genus are briefly noted.

Evolution of sexual dimorphism in phenotypic covariance structure in Phymata.

Sexual dimorphism is a consequence of both sex-specific selection and potential constraints imposed by a shared genetic architecture underlying sexually homologous traits. However, genetic architecture is expected to evolve to mitigate these constraints, allowing the sexes to approach their respective optimal mean phenotype. In addition, sex-specific selection is expected to generate sexual dimorphism of trait covariance structure (e.g., the phenotypic covariance matrix, P), but previous empirical work has not fully addressed this prediction. We compared patterns of phenotypic divergence, for three traits in seven taxa in the insect genus Phymata (Reduviidae), to ask whether sexual dimorphism in P is common and whether its magnitude relates to the extent of sexual dimorphism in trait means. We found that sexual dimorphism in both mean and covariance structure was pervasive but also that the multivariate distance between sex-specific means was correlated with sex differences in the leading eigenvector of P, while accounting for uncertainty in phylogenetic relationships. Collectively, our findings suggest that sexual dimorphism in covariance structure may be a common but underappreciated feature of dioecious populations.