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.

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.

Cloning and reproductive regulation of a trypsin precursor gene in Adelphocorissuturalis.

Adelphocoris suturalis is a major pest of cotton. Here, we identified a trypsin precursor gene (AsTryP) in A. suturali, which has an open reading frame region of 873 bp and belongs to the trypsin superfamily. The mRNA of the AsTryP gene was detectable in every life stage and different tissues of 8-day-old females, and the gene was highly expressed in fourth-instar nymphs and the thorax of 8-day-old females. Down-regulation of AsTryP by the injection of double-stranded RNA suppressed the ovarian development and female fertility. These results reveal that trypsin precursor is involved in the reproductive process of A. suturali, and may facilitate the development of new strategies for a better control of A. suturalis.

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.

Revision of Limnocoris Stål (Heteroptera: Nepomorpha: Naucoridae) of the tropical Andes.

The species of Limnocoris of the tropical Andes of South America are revised, including the descriptions of eight new species: L. chrysosetosus n. sp. from Ecuador; L. elongatus n. sp. and L. emboliatus n. sp. from Colombia; L. molanoi n. sp. from Colombia and Ecuador; L. luisae n. sp. from Colombia and Venezuela; L. longirostris n. sp. from Venezuela; L. nieseri n. sp. from Colombia, Ecuador, and Panama; and L. reynosoi n. sp. from Brazil, Colombia, and Venezuela. Further, supplemental descriptions are provided for the previously described species. The following taxa are resurrected from synonymy and their species status are restored: Limnocoris peruvianus Melin stat. restit. from synonymy with L. pectoralis Montandon, and L. stali Montandon stat. restit. from synonymy with L. borellii Montandon. The following synonymies are proposed, with junior synonyms in brackets: L. borellii Montandon [L. horvathi Montandon n. syn.], L. dubiosus Montandon [L. aymarana Poisson n. syn.], L. malkini La Rivers [L. pulchellus n. syn.], L. obscurus Montandon [L. trilobatus Nieser, González, Eichelkraut, n. syn.], L. ochraceus Montandon [L. maculatus De Carlo n. syn.], L. pallescens (Stål) [L. bergrothi Montandon n. syn.], L. pectoralis Montandon [L. rivalis Melin n. syn.], L. peruvianus Melin [L. calii Nieser, González Eichelkraut n. syn.] and L. stali Montandon [L. robustus Roback Nieser n. syn., L. carcharus La Rivers n. syn.]. Lectotypes are designated for five species: L. aymarana, L. bergrothi, L. borellii, L. dubiosus, and L. stali. An illustrated taxonomic key and distribution maps also are presented.

Illustrated key to the species included in the genus Petalops Amyot amp; Serville, 1843 (Hemiptera: Heteroptera: Coreidae: Coreinae: Acanthocephalini), with description of four new species and new distributional notes.

Four new species of Petalops Amyot Serville, 1843 are described: P. graziae from Brazil, P. jactatus from Ecuador, P. lautus from Colombia, and P. necopinus from Peru. A revised key to all known species (16) is included. New distributional data are given for P. ambiguous Brailovsky, 1991, P. bellator Brailovsky, 1991, P. luteomaculosus Brailovsky, 1991, P. occulta Brailovsky, 1991, and P. thoracicus (Thunberg), 1783. Dorsal view photos are added of all the known species.

Ammianus pericarti sp. n. (Hemiptera: Heteroptera: Tingidae), the first strictly Palaearctic representative of the genus with a key to the species of the Ammianus junodi group.

Ammianus pericarti sp. n., the first strictly Palaearctic representative of the genus, is described from Agadir (Morocco) as new to the science. The species is illustrated and compared to all its morphologically similar representatives of the Ammianus junodi group; a key to this species group is also provided. Moreover, A. vanderijsti (Schouteden, 1923) is reported for the first time from the Republic of South Africa.

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.

To the nomenclature of two species of the genus Adomerus (Heteroptera: Cydnidae).

The study of the lectotype of Sehirus fuscipennis Horváth, 1899 showed that this specimen is conspecific with Canthophorus maculipes sensu Aukema Constant, 2016 and Adomerus maculipes sensu Gapon, 2018. To promote stability of nomenclature, the neotype of Cydnus maculipes Mulsant et Rey 1852 is designated instead of the lost syntypes. The name Sehirus aeneus Walker, 1867 is placed in synonymy with Adomerus maculipes (Mulsant et Rey, 1852). The name Adomerus fuscipennis (Horváth, 1899), stat. resurr. is reinstated. Colouration of the hemelytra, the structure of the parameres and aedeagi of the holotype of S. aeneus Walker, 1867 (female), of a male of A. maculipes, being topotypic with the latter, and of the lectotype of S. fuscipennis Horváth, 1899 are compared with each other and with descriptions of the terminalia of both species, recently published by the second author based on material from different localities. A map of the distribution of both species is given according to the literature data and studied collection materials.

Taxonomic updates on the Mecocephala group (Hemiptera: Pentatomidae): Redescription of 'Hypatropis complex', with a review of genitalic terminology and new records.

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.

emCallivelia/em, a new genus for certain Neotropical Veliinae (Heteroptera: Veliidae), including description of a new species.

The new genus Callivelia is proposed to hold three Neotropical species previously held within Paravelia: type-species Callivelia conata (Hungerford), Callivelia taipiensis (Cheesman) and Callivelia bipunctata (Rodrigues, Moreira, Nieser, Chen Melo). Paravelia virtutis (Drake Harris) 1935 is synonymized under Callivelia taipiensis (Cheesman) 1926. In addition, a new species, C. anomala, is described from the Amazon Basin of Brazil. Additional distributional records are provided for the three previously described species treated, including the first country record for C. bipunctata in Paraguay. A key to the species of Callivelia is provided, accompanied by color habitus photographs for all three species, and additional photographs of key generic characters.

Two new species of emOcyochterus/em (Heteroptera: Ochteridae) from Ecuador and Panama.

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.

Water bugs (Hemipera: Heteroptera: Nepomorpha amp; Gerromorpha) of Chile: phylogenetic and biogeographic considerations, and a catalog of the fauna.

The Chilean fauna of water bugs comprises seven species of semi-aquatic bugs (Heteroptera: Gerromorpha), representing five genera, three tribes, four subfamilies and four families; and 27 species and one subspecies of aquatic bugs (Heteroptera: Nepomorpha), representing four subgenera, eight genera, three tribes, seven subfamilies, and five families. We compare the fauna with neighboring countries and find that several otherwise widespread and abundant taxa are missing in Chile, but that Chepuvelia usingeri China, 1963 (Macroveliidae), Microvelia chilena Drake Hussey, 1955 (Veliidae), Limnocoris dubiosus Montandon, 1898 (Naucoridae), Nerthra (Nerthra) parvula (Signoret, 1863), N. (N.) undosa Nieser Chen, 1992, N. (Rhinodermacoris) praecipua Todd, 1957 (Gelastocoridae), and Sigara (Tropocorixa) termasensis (Hungerford, 1928a) (Corixidae) are endemic to the country. To this list, we add †Nerthra (Nerthra) subantarctica Faúndez Ashworth, 2015, even though the species is only known from a subfossil. We can also inform that while water bugs are found in the archipelagoes of southern Chile, no species has been reported from the Juan Fernandez Islands, Easter Island and other off-shore islands. Several of the Chilean species are without any close extant relatives, such as C. usingeri and Aquarius chilensis (Berg, 1881) (Gerridae), or with relatives in Oceania (N. praecipua), suggesting that historical events such as dispersal and extinction have had a major influence on the composition of the Chilean fauna.

A review of emCryphocricos/em Signoret, 1850 (Naucoridae: Cryphocricinae) with descriptions of three new species.

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.

Revision of the emBelostoma triangulum/em group (Insecta: Heteroptera: Belostomatidae).

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.

Survey of the semiaquatic bugs (Hemiptera: Heteroptera: Gerromorpha) from Alagoas and Sergipe, Northeast Brazil.

A survey of the semiaquatic bugs (Hemiptera: Heteroptera: Gerromorpha) from Alagoas and Sergipe, Northeast Brazil, is presented. Specimens have been obtained mainly during three expeditions carried out in 2018 and 2019. Individuals of 40 species, representing the following 18 genera and five families have been recorded: Brachymetra Mayr, 1865, Cylindrostethus Mayr, 1865, Limnogonus Stål, 1868, Neogerris Matsumura, 1913, Tachygerris Drake, 1957, Rheumatobates Bergroth, 1892, Halobatopsis Bianchi, 1896, Ovatametra Kenaga, 1942 (Gerridae); Lipogomphus Berg, 1879, Merragata White, 1877 (Hebridae); Hydrometra Latreille, 1797 (Hydrometridae); Mesovelia Mulsant Rey, 1852 (Mesoveliidae); Husseyella Herring, 1955, Microvelia Westwood, 1834, Rhagovelia Mayr, 1865, Paravelia Breddin, 1898, Platyvelia Polhemus Polhemus, 1993 and Stridulivelia Hungerford, 1929 (Veliidae). Alagoas and Sergipe have 35 and 31 new records, respectively. Rheumatobates trinitatis (China, 1943) and Rhagovelia plumbea Uhler, 1894 are recorded for the first time from Brazil.

A new species of emMicrovelia/em Westwood, 1834 (Hemiptera: Heteroptera: Veliidae) from southeastern Brazil.

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.

Revision of the emRhagovelia/em emangustipes/em complex (Insecta: Hemiptera: Veliidae) from Colombia.

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.

Description of a new species and new records of Gerromorpha (Insecta: Hemiptera: Heteroptera) from Panama and Colombia.

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).