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We describe the first and third larval instars of Hydrocanthus levigatus (Brullé, 1837), including morphometric and chaetotaxic analyses of the cephalic capsule, head appendages, legs, last abdominal segment, and urogomphus. Larvae of this species have many dark dorsal maculae on the body, similar to those of H. socius Sahlberg, 1844 and H. debilis Sharp, 1882. First instar larvae of H. levigatus can be separated from those of H. socius and H. debilis by the following combination of characters: large size and seta TI5 somewhat longer than tibial length on mesothoracic and metathoracic legs. Conversely, the third instar of H. levigatus differs from those of H. socius and H. debilis in the greater number of secondary setae on the legs. [ABSTRACT FROM AUTHOR]

Copyright of ZooKeys is the property of Pensoft Publishers and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of ZooKeys is the property of Pensoft Publishers and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The third-instar larva of Suphisellus curtus (Sharp, 1882) is described and illustrated for the first time, including morphometric and chaetotaxic analyses of the cephalic capsule, head appendages, legs, last abdominal segment, and urogomphus. This is the second detailed larval description for the genus Suphisellus Crotch, 1873. Larvae of this genus can be readily separated from other known noterid larvae by the strongly developed galea, subequal in length to maxillary palpus. Suphisellus curtus differs from S. rufipes (Sharp, 1882) in the dorsal colour pattern, S. rufipes being entirely testaceous and S. curtus testaceous with transverse brown bands between body segments. [ABSTRACT FROM AUTHOR]

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The larvae of five Nearctic species of Ilybiosoma Crotch, 1873, I. bjorkmanae (Hatch, 1939), I. lugens (LeConte, 1852), I. minnesotensis (Wallis, 1933), I. pandurus (Leech, 1942), and I. regularis (LeConte, 1852) are described for the first time including a detailed chaetotaxy analysis of the cephalic capsule, head appendages, legs, last abdominal segment and urogomphi. A provisional parsimony analysis based on 55 informative larval characteristics of 18 species in seven genera of the subfamily Agabinae was conducted using the program TNT. The larvae of the five Ilybiosoma species described were found to be fairly similar morphologically. Compared to the other species of Agabinae studied, larvae of Ilybiosoma stand out from most Agabini by the presence of the strongly emarginated siphon, which are reminiscent of the condition observed in Hydrotrupes Sharp, 1882 and Platynectes Régimbart, 1879. [ABSTRACT FROM AUTHOR]

The instar III larvae of the Australian endemic species Sternopriscus alpinus Hendrich and Watts, 2004, S. clavatus Sharp, 1882, S. hansardii (Clark, 1862) and S. multimaculatus (Clark, 1862) are described and illustrated for the first time. We explore implications for understanding the evolution of larval morphological traits amongst selected Sternopriscina genera. A parsimony analysis based on 84 larval characteristics of 11 species in six genera was conducted using the program TNT. Larvae of Sternopriscus Sharp, 1882 are characterised by the last abdominal segment not extending into siphon and by very elongate urogomphi. Sternopriscus is subdivided into two groups based either on absence or reduction in number of natatory setae along the dorsal margin of femora, tibiae and tarsi. Sternopriscus is postulated to be sister to a clade comprised of Chostonectes Sharp, 1882, Megaporus Brinck, 1943 and Antiporus Sharp, 1882. [ABSTRACT FROM AUTHOR]

The pygidial gland secretions of Hygrobiidae have traces of benzoic acid and 4 I - i hydroxybenzaldehyde, that in Dytiscidae make up some of the main gland constituents (Dettner, 1985, 1987, 2019). Indeed, Burmeister (1976) states (translated from German): 'Since the skeleton of I Hygrobia i and Dytiscidae has no derived features in the area of the ovipositor which do not also characterize I Amphizoa i , the possession of this [prothoracic defense] gland is considered a synapomorphy for I Hygrobia i and Dytiscidae and in the following scheme (fig. 52) this feature (26!) is listed'. Morphological view of relationships among Hygrobiidae, Dytiscidae and Amphizoidae Based on our review none of the morphological features cited by CEA unambiguously support a sister relationship between Hygrobiidae and Dytiscidae. 1C) with a sister-group relationship between Dytiscidae and Hygrobiidae [emphasis added]: 'The sister-group relationship between Hygrobiidae and Dytiscidae was proposed by Burmeister (1976) based on I morphology of the ovipositor i and by Ruhnau (1986) based on I larval morphology i . Beutel (1986) previously proposed this character as a synapomorphy of I Hygrobia i and I Amphizoa i LeConte as well, but suggested it also included Dytiscidae [translated from German]: 'This situation [of bifurcate pygidial glands] can possibly be regarded as a derived basic plan characteristic of the Amphizoidae + Hygrobiidae + Dytiscidae, whereby the unbranched pygidial gland of most Dytiscidae is interpreted as secondary'. [Extracted from the article]

Copyright of Revista Mexicana de Biodiversidad is the property of Universidad Nacional Autonoma de Mexico, Instituto de Biologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The instar III larva of Liocanthydrus clayae (J. Balfour-Browne, 1969) is described and illustrated, including morphometric and chaetotaxic analyses of the cephalic capsule, head appendages, legs, last abdominal segment, and urogomphus. Larvae of Liocanthydrus Guignot, 1957, can be readily separated from other known noterid larvae by the presence of two short posterodorsal projections on the last abdominal segment. Regarding chaetotaxy, Liocanthydrus differs from Suphis Aubé, 1836, Hydrocanthus Say, 1823 and Suphisellus Crotch, 1873 in the position of seta AN7, the shape of seta CO13, the shape and length of setae FE6 and TI7, and the length of seta UR8. [ABSTRACT FROM AUTHOR]

The larvae of three species of Agabus s. str. Leach, 1817, A. bifarius (Kirby, 1837), instar III, A. disintegratus (Crotch, 1873), instars I–III, and A. falli (Zimmermann, 1934), instars I–III, are described including for the first time a detailed chaetotaxy analysis of the cephalic capsule, head appendages, legs, last abdominal segment and urogomphi. Larvae of A. falli show several unique morphological features that differentiate them from those of the other species of Agabini studied. A provisional parsimony analysis based on 55 larval characteristics of 17 species in seven genera of the subfamily Agabinae was conducted using the program TNT. As a result of this analysis, Agabini was recovered as polyphyletic while Platynectini and Hydrotrupini are deemed monophyletic. [ABSTRACT FROM AUTHOR]

Burmese amber is well known for preserving unique extinct lineages of insects. Here, we describe a new fossil beetle in its larval stage from Burmese amber. Bayesian and parsimony phylogenetic analysis of 50 morphological characters support this fossil as being sister to both the tribes Dineutini and Orectochilini, representing an extinct stem lineage in Gyrininae. It is described here as a new genus and species of whirligig beetle, Chimerogyrus gigagalea gen. & sp. nov. , a taxon that preserves remarkable intermediate features between the whirligig beetle tribe Gyrinini and the crown Orectochilini and Dineutini. This new taxon preserves key features for studying the evolution of characters within the larval stage of the Gyrinidae and highlights the importance of Burmese amber for preserving both stem and crown lineages present during the mid-Cretaceous, before the end-Cretaceous mass extinction event. [ABSTRACT FROM AUTHOR]

The larvae of the Australian endemic species Chostonectes gigas (Boheman, 1858) and C. johnsonii (Clark, 1862) are described and illustrated for the first time, with detailed morphometric and chaetotaxic analyses of the cephalic capsule, head appendages, legs, last abdominal segment and urogomphi. A parsimony analysis based on 83 informative larval characteristics of six species in four genera of the subtribe Sternopriscina was conducted using the program TNT. The monophyletic origin of the four Sternopriscina studied was strongly supported. Members of Paroster Sharp, 1882 characterise by the presence of three labial palpomeres, a unique feature within the subfamily Hydroporinae. Larvae of Barretthydrus Lea, 1927, Antiporus Sharp, 1882 and Chostonectes Sharp, 1882 evolved the presence of natatory setae on femora, tibia and tarsi. At the moment, Chostonectes is postulated to be closely related phylogenetically to Antiporus in the context of this study. [ABSTRACT FROM AUTHOR]

In this contribution, the larval morphology of Spencerhydrus Sharp, 1882 was studied, an Australian endemic genus in the diving beetle tribe Cybistrini. All instars of the only two species included in the genus (S. latecinctus Sharp, 1882 and S. pulchellus Sharp, 1882) are described and illustrated with the exception of the third instar of S. latecinctus. Detailed morphometric and primary chaetotaxic analyses were performed to discover useful characters for generic diagnosis and species distinction. Spencerhydrus can be distinguished from other Cybistrini genera by the medial projection of frontoclypeus slightly indented apically, with lamellae clypeales directed forward in a characteristic V-shaped pattern, the median process of prementum strongly developed, the presence of a single ventral sclerite on prothorax, the presence of basoventral spinulae on claws, and the reduced sclerotization of the abdominal segment VII which covers only the anterior half. Larvae of the two species of Spencerhydrus can readily be distinguished by the shape of the median process of prementum, which is visibly broader in S. pulchellus than in S. latecinctus. [ABSTRACT FROM AUTHOR]

Hydrotrupes chinensis Nilsson, 2003 described from the holotype collected in Anhui Province, China, is newly recorded from three localities in Guangdong Province, ca. 750 km southwest from the type locality. The species seems to inhabit hygropetric habitats exclusively, with diurnal larvae and nocturnal adults hidden under stones or in cracks in rock during the day; when disturbed, the adults readily jumped off the rock surface. The adult is redescribed. The larvae are described and illustrated for the first time, with detailed morphometric and chaetotaxic analyses of the cephalic capsule, head appendages, legs, last abdominal segment, and urogomphi. Whereas similar morphologically to the Nearctic endemic Hydrotrupes palpalis Sharp, 1882, the first instar larva of H. chinensis distinguishes by presence of six lamellae clypeales, two additional spine-like setae both on the last abdominal segment and urogomphomere 1, and the strongly developed egg bursters. [ABSTRACT FROM AUTHOR]

Here we provide evidence that confinement in Robinson Crusoe Island (located about 660 km west of continental Chile) over evolutionary time leads to strong morphological modifications in diving beetle (Dytiscidae) larvae. We analysed a large set of morphological larval characters for all currently recognised genera of Colymbetinae as a framework, to infer phylogenetic relationships within the large genus Rhantus Dejean, 1833 and, in particular, of the charismatic Juan Fernández diving beetle, Rhantus selkirki Jäch, Balke & Michat, 2015, comparing our results with a recent phylogeny of the Colymbetinae based on DNA sequence data. We suggest that adaptation to the island's particular habitats resulted in the reversal of certain characters of R. selkirki back to the plesiomorphic states. This may cause the species to be erroneously interpreted as more ‘primitive’ if only morphological characters are analysed. Confinement in the particular, shallow and barely vegetated aquatic habitats of Robinson Crusoe Island for a long time seems to have led to this divergent morphology, particularly in characters related to swimming ability such as several leg and urogomphal setae. In this way, R. selkirki larvae secondarily resemble those of some earlier diverging dytiscid lineages such as Agabinae and Copelatinae, which typically creep on the bottom of water bodies and do not swim well. [ABSTRACT FROM AUTHOR]

The larvae of the Malagasy whirligig beetle Dineutus sinuosipennis Laporte, 1840, identified using DNA sequence data, are described and illustrated for the first time, including detailed morphometric and chaetotaxic analyses of selected structures and a description of larval habitat. Larvae of the genus Dineutus Macleay, 1825 are diagnosed, and a key to identify the genera of the tribe Dineutini is presented. Larvae of Dineutus exhibit the characters traditionally recognized as autapomorphies of the Gyrinidae: body less sclerotized, egg bursters located on the parietal, one additional sensorial plate on the third antennomere, cardo and lacinia well developed, prementum completely divided, abdominal tracheal gills, and four terminal hooks on the pygopod. They also share with larvae of the other Dineutini genera these putative synapomorphies: numerous minute pore-like additional structures on the ultimate maxillary and labial palpomeres, coxal primary seta CO12 inserted submedially, and trochanteral primary seta TR2 absent. Larvae of Dineutus can be distinguished from those of other known genera of Dineutini by the posterior margin of the lacinia not dentate, tracheal gills plumose, parietal seta PA5 inserted relatively far from setae PA7-9, mandibular pores MNb and MNc inserted relatively far from each other, and tarsal seta TA1 inserted submedially. [ABSTRACT FROM AUTHOR]

A comprehensive higher-level phylogeny of diving beetles ( Dytiscidae) based on larval characters is presented. Larval morphology and chaetotaxy of a broad range of genera and species was studied, covering all currently recognized subfamilies and tribes except for the small and geographically restricted Hydrodytinae, where the larva is unknown. The results suggest several significant conclusions with respect to the systematics of Dytiscidae including the following: monophyly of all currently recognized subfamilies, although Dytiscinae when considered in a broad context is rendered paraphyletic by Cybistrinae; currently recognized tribes are monophyletic except for Agabini, Hydroporini and Laccornellini; inter-subfamily and inter-tribe relationships generally show weak support, except for a few well supported clades; three distinct clades are recognized within Dytiscinae [ Dytiscini sensu lato (i.e. including the genera Dytiscus Linnaeus and Hyderodes Hope), Hydaticini sensu lato, and Cybistrini]; and recognition of Pachydrini as a distinct tribe. Other less robust results include: Methlini sister to the rest of Hydroporinae; relative basal position of Laccornini, Hydrovatini and Laccornellini within Hydroporinae; close relationship of Agabinae and Copelatinae; Matinae nested deep within Dytiscidae, as sister to a large clade including Colymbetinae, Coptotominae, Lancetinae and Dytiscinae sensu lato; the sister-group relationship of Agabetini and Laccophilini is confirmed. The results presented here are discussed and compared with previous phylogenetic hypotheses based on different datasets, and the evolution of some significant morphological features is discussed in light of the proposed phylogeny. All suprageneric taxa are diagnosed, including illustrations of all relevant synapomorphies, and a key to separate subfamilies and tribes is presented, both in traditional (paper) format and as an online Lucid interactive identification key. [ABSTRACT FROM AUTHOR]

The origin of biodiversity in the Neotropics predominantly stems either from Gondwana breakup or late dispersal events from the Nearctic region. Here, we investigate the biogeography of a diving beetle clade whose distribution encompasses parts of the Oriental region, the Indo-Australian archipelago (IAA) and the Neotropics. We reconstructed a dated molecular phylogeny, inferred diversification dynamics and estimated ancestral areas under different biogeographic assumptions. For the Oriental region and the IAA, we reveal repeated and complex colonization patterns out of Australia, across the major biogeographic lines in the region (e.g. Wallace's Line). The timing of colonization events across the IAA broadly coincides with the proposed timing of the formation of major geographic features in the region. Our phylogenetic hypothesis recovers Neotropical species nested in two derived clades. We recover an origin of the group in the early Eocene about 55 million yr ago, long after the break-up of Gondwana initiated, but before a complete separation of Australia, Antarctica and the Neotropics. When allowing an old Gondwanan ancestor, we reconstruct an intricate pattern of Gondwanan vicariance and trans-Pacific long-distance dispersal from Australia toward the Neotropics. When restricting the ancestral range to more plausible geological area combinations in the Eocene, we infer an Australian origin with two trans-Pacific long-distance dispersal events toward the Neotropics. Our results support on one hand a potential Gondwanan signature associated with regional extinctions in the Cenozoic and with Antarctica serving as a link between Australia and the Neotropics. On the other hand, they also support a trans-Pacific dispersal of these beetles toward the Andean coast in the Oligocene. [ABSTRACT FROM AUTHOR]

A new species of Aciliini diving beetles,Thermonectus tremouillesisp. nov., is described on the basis of adult and larval specimens collected in shaded forest ponds in Argentina. The adults are compared with morphologically close species and diagnosed by the following combination of characters: the colour pattern on pronotum and elytra; the sexual sculpture of the female well marked, covering basal fourth to basal half of elytra; the male protibia narrow with dorsal margin slightly prominent; the tergite IX of male with four posterior projections; the median lobe of aedeagus bifid apically; and the parameres bearing a terminal spur. The larvae, for their part, are compared with those of other species of the genus and diagnosed by the colour pattern of the cephalic capsule, the shape of the nasale, the spinulae on the prementum, and several chaetotaxic features. Both adults and larvae are illustrated in detail combining scanning electron microscope images, digital photos and line drawings of selected structures. The habitat of the new species and its associated fauna are briefly described. [ABSTRACT FROM AUTHOR]

The larvae of the grooved whirligig beetleMacrogyrus oblongus(Boisduval, 1835) are described and illustrated including detailed morphometric and chaetotaxic analyses of selected structures. Larvae ofMacrogyrusRégimbart, 1882 exhibit the characters traditionally recognised as autapomorphies of the Gyrinidae. The first instars bear egg bursters on the parietal, a potential additional autapomorphy. Putative larval autapomorphies of the tribe Dineutini are the presence of additional setae on the mandible, the absence of the seta TR2, and the presence of pore-like additional structures on the ultimate palpomeres.Macrogyruslarvae differ from those of the other known dineutine genera (AndogyrusOchs, 1924 andDineutusMacLeay, 1825) in the absence of a neck constriction and in the distal position of the pore LAc. Other useful characters to distinguish genera within Dineutini are the presence or absence of additional setae on the cardo and coxa, and the posterior margin of the lacinia dentate or smooth. [ABSTRACT FROM PUBLISHER]

The superfamily Dytiscoidea contains six families with an aquatic lifestyle, with most of its extant diversity in two families: the burrowing water beetles ( Noteridae) and the diving beetles ( Dytiscidae). The other families have few species (up to six) and generally highly disjunct extant distributions. Aspidytidae currently contains one genus with two species, one in China and one in South Africa. Here we provide the first molecular data for the Chinese species, allowing us to explore the phylogenetic relationships and position of both species of this small family for the first time. Based on a matrix of 11 genes we inferred a phylogenetic hypothesis for Dytiscoidea including all extant families. Unexpectedly, Aspidytidae were consistently recovered as paraphyletic relative to Amphizoidae, despite being well characterized by apparently synapomorphic adult features. A re-examination of larval characters in the two aspidytid species revealed that the larva of the Chinese species is strikingly similar to that of Amphizoidae. Both share a series of plesiomorphic features but also some potential synapomorphies, including a dense vestiture of short setae on the head capsule, anteriorly shifted posterior tentorial grooves and widely separated labial palps. Arguably these features may belong to the groundplan of the clade Aspidytidae + Amphizoidae, with far-reaching secondary modifications (including reversals) in the South African A spidytes niobe. At present we retain the family Aspidytidae, however, due to the strong adult morphological synapomorphies of the two extant species, and the fact that the molecular paraphyly of the family may result from the highly divergent nature of the two extant species. This long evolutionary separation and strong divergence, in terms of gene sequences and larval features, is undeniable, substantial levels of saturation in third codon positions of protein-coding genes being present between the two taxa. We address this issue taxonomically by introducing the new genus S inaspidytes gen. nov. for the Chinese A spidytes wrasei. The continued contentious relationships amongst Dytiscidae, Hygrobiidae, Aspidytidae and Amphizoidae highlight the need for more data to address dytiscoid phylogenetics, possibly involving a genomic approach. © 2016 The Linnean Society of London [ABSTRACT FROM AUTHOR]

The phylogenetic relationships of the Australasian diving beetle genus Sternhydrus Brinck, 1945 were studied based on a cladistic analysis of 16 taxa and 112 morphological larval characters. Larvae of S. atratus (F., 1801) were described and illustrated in detail with particular emphasis on morphometry and ehaetotaxy. Primary chaetotaxy were unknown for the genus. The results supported the inclusion of Sternhydrus in a clade of Australian Cybistrini genera along with Onychohydrus Schaum and White, 1847 and Spencerhydrus Sharp, 1882 based on four synapomorphies: presence of additional pores on antennomere 1, tibial seta TI7 short and spine-like, and urogomphi longer than broad, included in the nonsclerotized ventrodistal area surrounding the anus. A sister group relationship of Sternhydrus and Onychohydrus is suggested by two synapomorphies: lateral projections of frontoclypeus serrate, and row of additional anteroventral setae on meso- and metatarsus composed of several thin setae of variable length. The genus Sternhydrus is characterized by two autapomorphies: presence of both spine-like and hair-like additional setae on the ventral surface of the femur, and absence of primary pores on the urogomphus. [ABSTRACT FROM AUTHOR]

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Anisomeriini diving beetles contain only two enigmatic species, representing a remarkable disjunction between the Pacific Juan Fernández Islands ( Anisomeria bistriata) and the South Atlantic Tristan da Cunha Archipelago ( Senilites tristanicola). They belong to the Colymbetinae, which contain 140 species worldwide. Here we aim to reconstruct the evolutionary history of the Anisomerinii and use > 9000 bp DNA sequence data from 13 fragments of 12 loci for a comprehensive sampling of Colymbetinae species. Analyses under different optimization criteria converge on very similar topologies, and show unambiguously that Anisomeria bistriata and Senilites tristanicola belong to the Neotropical Rhantus signatus species group, a comparatively recent clade within Colymbetinae. Anisomeriini therefore are synonomized with Colymbetini and both species are transferred to Rhantus accordingly, resulting in secondary homonymy of Rhantus bistriatus (Brullé, 1835) with Rhantus bistriatus (Bergsträsser, 1778). We propose the replacement name Rhantus selkirki Jäch, Balke & Michat nom. nov. for the Juan Fernández species. Presence of these species on remote islands is therefore not relictary, but the result of more recent range expansions out of mainland South America. Finally, we suggest that Carabdytini should be synonymized with Colymbetini. Our study underpins the Hennigian principle that a natural classification can be derived only from the search for shared apomorphies between species, not from differences. [ABSTRACT FROM AUTHOR]

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Background: Many scientific disciplines rely on correct taxon delineations and identifications. So does a great part of the general public as well as decision makers. Researchers, students and enthusiastic amateurs often feel frustrated because information about species remains scattered, difficult to access, or difficult to decipher. Together, this affects almost anyone who wishes to identify species or verify identifications. Many remedies have been proposed, but we argue that the role of natural history collections remains insufficiently appreciated. We suggest using state-of-the-art mass imaging technology and to join forces to create a global natural history metacollection on the internet, providing access to the morphology of tens of millions of specimens and making them available for automated digital image analysis. Discussion: Robotic high-resolution imaging technology and fast (high performance) computer-based image stitching make it now feasible to digitize entire collection drawers typically used for arthropod collections, or trays or containers used for other objects. Resolutions of 500 megapixels and much higher are already utilized to capture the contents of 40x50 cm collection drawers, providing amazing detail of specimens. Flanked by metadata entry, this helps to create access to tens of thousands of specimens in days. By setting priorities and combining the holdings of the most comprehensive collections for certain taxa, drawer digitizing offers the unique opportunity to create a global, virtual metacollection. The taxonomic and geographic coverage of such a collection could never be achieved by a single institution or individual. We argue that by joining forces, many new impulses will emerge for systematic biology, related fields and understanding of biodiversity in general. Digitizing drawers containing unidentified, little-curated specimens is a contribution towards the beginning of a new era of online curation. It also will help taxonomists and curators to discover and process the millions of "gems" of undescribed species hidden in museum accessions. Summary: Our proposal suggests creating virtual, high-resolution image resources that will, for the first time in history, provide access for expert scientists as well as students and the general public to the enormous wealth of the world's natural history collections. We foresee that this will contribute to a better understanding, appreciation and increased use of biodiversity resources and the natural history collections serving this cause. [ABSTRACT FROM AUTHOR]

The three larval instars of Brachyvatus acuminatus (Steinheil, 1869) (the type species of the bidessine genus Brachyvatus Zimmermann, 1919) are described and illustrated for the first time including detailed morphometric and chaetotaxic analyses of the cephalic capsule, head appendages, legs, last abdominal segment and urogomphi. Larvae of this genus are characterized by the absence of the primary pore ABc, which is a synapomorphy of the tribe Bidessini. Brachyvatus larvae can be separated from those of all other known Bidessini genera by the following combination of characters: very small size; lateral branches of nasale well visible in dorsal view; ventroapical spinula on third antennomere absent; meso- and metatergite of instar I with anterotransverse carina; siphon short; long urogomphi with secondary setae; seta PA3 absent; setae UR2 and UR4 inserted contiguously; natatory setae present on tibiae in instars II-III. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Entomologist is the property of Cambridge University Press and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista de la Sociedad Entomológica Argentina is the property of Sociedad Entomologica Argentina and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista de la Sociedad Entomológica Argentina is the property of Sociedad Entomologica Argentina and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The phylogenetic relationships and putative monophyly of the diving-beetle tribe Vatellini are explored based on a cladistic analysis of 37 taxa and 122 chaetotaxic and morphological characters from larvae. For this purpose, larvae of the genus Derovatellus Sharp are described and illustrated in detail, with particular emphasis on morphometry and chaetotaxy, with the later being unexplored until now. The results strongly support the monophyly of the Vatellini based on several unique larval characters. The terminal insertion of the primary seta UR8 on the second urogomphomere in members of Vatellini represents a reversal from the derived condition. Vatellini was recovered as the sister group of the Australian genus Antiporus Sharp (Hydroporini) based on the presence of: a spatulate nasale, pore PAe and elongate lateral spinulae on prementum. These characters, however, have a reduced value because all of them seem to have evolved several times independently within the Hydroporinae. The tribe Vatellini and its genera are diagnosed and compared with other hydroporine taxa, and interesting features are discussed. Vatellus Aubé is unique within Hydroporinae in the presence of secondary setae on the first antennomere and the first maxillary palpomere, and the one-segmented labial palpus. Derovatellus can be separated from almost every other Hydroporinae by the absence of seta LA1 on prementum and of secondary anterodorsal setae on femur. [ABSTRACT FROM AUTHOR]

The three larval instars of the type species of the bidessine genus Allodessus Guignot (A. bistrigatus (Clark)) are described and illustrated for the first time including detailed morphometric and chaetotaxic analyses of the cephalic capsule, head appendages, legs, last abdominal segment and urogomphi. Larvae of this genus are characterised by the absence of the primary pore ABc, which is a synapomorphy of the tribe Bidessini, and the presence of secondary setae on the urogomphi, which suggest a close phylogenetic relationship with Amarodytes Régimbart. Allodessus larvae are further characterised by a short last abdominal segment, long urogomphi, absence of colour pattern on the body, presence of a ventroapical spinula on the third antennomere, presence of pore PAk, presence of posterior secondary setae on coxa, presence of a large number of secondary setae on coxa, presence of posteroventral secondary setae on tarsus, and presence of a total of 6–7 (instar II) and 7–11 (instar III) secondary setae on metatarsus. This combination of characters separates larvae of Allodessus from those of the other known Bidessini genera. [ABSTRACT FROM AUTHOR]

El artículo presenta los resultados del primer inventario de coleóteros acuáticos y semiacuáticos del Parque Provincial Ernesto Tornquist, localizado en la provincia de Buenos Aires, Argentina. Los autores incluyen una introducción sobre el parque en el cual se realizó el estudio, así como una descripción del material y los métodos utilizados.

The phylogenetic relationships of the diving-beetle (Dytiscidae) subfamily Copelatinae are not well known. Some authors postulated a sister-group relationship between Copelatus Erichson and the remaining Dytiscidae, relying mainly on the absence of a mandibular channel in Copelatus. Other authors suggested a more derived position of the genus. Larval characters have been underutilized in phylogenetic studies, mainly because the larvae of many taxa within the family and, in particular, within Copelatinae are unknown. A comprehensive approach aimed to study the phylogenetic placement of a member of this subfamily based on larval characters has not been produced so far. In this study, the phylogenetic relationships of Copelatus are explored based on a cladistic analysis of 24 taxa and 120 chaetotaxic and morphological characters from larvae. For this purpose, larvae of Copelatus longicornis Sharp are described and illustrated in detail for the first time, with particular emphasis on morphometry and chaetotaxy, with the latter being unexplored until now. The results support a derived position of Copelatus within Dytiscidae, with a sister-group relationship between this genus and a clade formed by the subfamilies Lancetinae, Coptotominae, Laccophilinae, Colymbetinae, Matinae, and Dytiscinae, and part of Agabinae. No evidence was found for a sister-group relationship between Copelatus and the remaining Dytiscidae so that the absence of a mandibular channel in this genus is likely a reduction. Copelatus is supported by three apomorphies within Dytiscidae: mandibular channel absent, internal margin of the stipes with three robust spinulae, and seta MX8 inserted subapically on the galea. [ABSTRACT FROM AUTHOR]

Larvae of all three instars of the diving-beetle species Notaticus fasciatus Zimmermann (Coleoptera: Dytiscidae) are described and illustrated in detail, with particular emphasis on chaetotaxy and morphometry, and the phylogenetic relationships of the genus Notaticus Zimmermann within Dytiscidae are investigated based on a cladistic analysis of 66 larval characters. Including Notaticus in its own subfamily, as is sometimes done, would result in Dytiscinae paraphyletic with respect to Aubehydrinae. Notaticus is found to be distinctive within Dytiscinae, being characterized by several apomorphies, including pore FRf and occipital suture absent, seta AN1 inserted distally on antennomere 3, seta MX8 subapical and pore MXh submedial on galea, pore LAc basal on labial palpomere 2, and abdominal segment VII completely sclerotized ventrally in instar I. Inclusion of Notaticus in a distinct tribe (Aubehydrini) seems warranted. A subordinate position of Notaticus within Dytiscinae is proposed, with Aubehydrini being part of a clade along with Hydaticini, Aciliini, and Eretini. Support is presented for a clade Aubehydrini + Aciliini + Eretini based on the presence in these taxa of a gibbous larva, short rounded spinulae on antennomere one in instar I, and a strongly developed and spiniform galea with the seta MX9 inserted subapically on it. It is postulated that Aubehydrini is sister to the clade Aciliini + Eretini. A key separating larvae of the tribes of Dytiscinae is presented. [ABSTRACT FROM AUTHOR]

Copyright of Revista de la Sociedad Entomológica Argentina is the property of Sociedad Entomologica Argentina and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista de la Sociedad Entomológica Argentina is the property of Sociedad Entomologica Argentina and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista de la Sociedad Entomológica Argentina is the property of Sociedad Entomologica Argentina and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista de la Sociedad Entomológica Argentina is the property of Sociedad Entomologica Argentina and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista de la Sociedad Entomológica Argentina is the property of Sociedad Entomologica Argentina and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The first instar of Laccornellus lugubris (Aubé) is described. A parsimony analysis of selected taxa of the subfamily Hydroporinae based on 48 informative larval characters was conducted using the program PAUP*. The 100 most parsimonious trees support a placement of Laccornellus Roughley & Wolfe outside the tribe Hydroporini as part of a clade made up of Hydrovatus Motschulsky + Canthyporus Zimmermann, which is supported by the absence of the primary seta UR8 and of the primary seta LA2, and the spine-like condition of the primary seta AB10. Larvae of Laccornellus evolved one unique character state within the Hydroporinae, which is the presence of the primary seta AB15 on ventral surface of last abdominal segment. [ABSTRACT FROM AUTHOR]

The three larval instars of Hydaticus (Guignotites) tuyuensis Trémouilles are described and illustrated for the first time, emphasizing the morphometry and chaetotaxy. Second- and third-instar larvae of the known species of the subgenus Guignotites Brinck are characterized by a trilobate median process of prementum. All larval instars of H. tuyuensis, however, have a bilobate process, similar to that present in the known species of the subgenus Hydaticus Leach. This implies that a trilobate process cannot be used as a diagnostic character for Guignotites. Alternatively, Guignotites as presently defined may not represent a natural group. A cladistic analysis of 57 larval characters suggests that the genus Hydaticus shares a common origin with the clade composed of the genera Eretes Laporte and Thermonectus Dejean, based on the following synapomorphies: (i) abdominal segment VII almost completely sclerotized ventrally; the absence of (ii) additional ventroapical pores on the third antennomere, (iii) setae FE4 and FE6, (iv) additional setae on the femur and (v) additional setae on the tibia; and the presence of (vi) setae on the median process of prementum and (vii) spinulae on the second labial palpomere. A bilobate or trilobate median process of the prementum and the submedial insertion of seta AN3 distinguish Hydaticus from the remaining genera of Dytiscinae studied. [ABSTRACT FROM AUTHOR]

The three larval instars of Thermonectus succinctus (Aubé 1838) are described and illustrated for the first time, emphasizing the morphometry and chaetotaxy. Biological notes are included. Thermonectus Dejean is distinguished from other Aciliini genera by its slightly bifid median process of the prementum, which bears two spine-like setae (LA8). First instars of T. succinctus differ from those of Acilius Leach and Graphoderus Dejean in the lower number of additional anterodistal setae on the femur. The shape of seta TA1 and the presence of an additional posterior pore on the tibia separate first instars of Graphoderus from those of Acilius and T. succinctus . Regarding the mature larva, T. succinctus differs from T. alfredi Griffini 1898 in its smaller size, from T. basillaris (Harris 1829) in the lack of a row of minute hairs along the internal margin of the galea, and from T. nigrofasciatus ornaticollis (Aubé 1838) in the shorter length of seta LA8. [ABSTRACT FROM AUTHOR]

Abstract All the preimaginal stages of Lancetes marginatus (Steinheil) and third instar larva of L. biremis Říha are described and figured for the first time. Detailed analyses of the morphometry, chaetotaxy and porotaxy are provided, and comparisons with the immatures of other species of the genus are included. The larvae described have multifragmented urogomphi, the only larval synapomorphy that defines the genus Lancetes Sharp. Third instars also present a secondary subdivision in some of the cephalic appendages, which is a synapomorphy of Lancetes plus Dytiscinae. First instar larva of L. marginatus is distinguished from the remaining known first instars of Lancetes by the absence of primary pores FRe and MXa, and the presence of one additional minute seta on the dorsal surface of antennomere 4 and one additional pore on the urogomphus. The third instar of L. marginatus is unique by the absence of secondary dorsal setae on the femur. The pupa of L. marginatus differs from that of L. angusticollis by the presence of fewer setae on the head, pronotum and abdominal terga V to VIII. [ABSTRACT FROM AUTHOR]

Copyright of Revista de la Sociedad Entomológica Argentina is the property of Sociedad Entomologica Argentina and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)