The Gyrinidae (Coleoptera) fauna of Thailand: Key to tribes and genera, with new records and keys to species of Dineutini and Gyrinini.

Eighteen species and four genera of the family Gyrinidae are recorded from Thailand. Seven species, belonging to three genera in the tribes Dineutini and Gyrinini, are here treated in detail. Dineutus sitesi Gustafson, Hjek Miller, D. spinosus (Fabricius), D. unidentatus Aub, Porrorhynchus marginatus Laporte and Gyrinus sericeolimbatus Rgimbart were already known, whereas D. australis (Fabricius) and Gyrinus smaragdinus Rgimbart are recorded for the first time. Diagnoses, distribution maps and keys to tribes, genera, and all species of Dineutus and Gyrinus occurring in Thailand are provided. The fourth genus, Patrus (tribe Orectochilini), has been partly revised in a preceding paper.

Review of the Patrus landaisi species group from Thailand with description of three new species (Coleoptera, Gyrinidae).

A survey of the whirligig beetles of the genus Patrus Aubé, 1838 occurring in Thailand belonging to the newly designated Patrus landaisi species group is presented. Three new species are described and illustrated: P. garuda sp. nov., P. nanensis sp. nov. and P. phetchabunensis sp. nov.; with P. apicalis (Régimbart, 1891), P. landaisi (Régimbart, 1892), and P. subapicalis (Ochs, 1930) stat. nov. being recorded for the first time in Thailand. Morphological and molecular analyses, together in an integrative approach, support the elevation of P. subapicalis to species status, instead of being a subspecies of P. apicalis. A diagnosis, illustrations of habitus and diagnostic characters, distribution maps, habitat images and a key to species are provided for all known members of the P. landaisi species group that occur in Thailand. A checklist of species in the group is also given.

Hydaticus aequalis sp. n. and a new record of H. devexus Trémouilles, 1996 from Brazil (Coleoptera, Dytiscidae, Hydaticini).

Hydaticus aequalis sp. n. is described from Brazil, where it was recently discovered in the central lowlands region of the Amazon forest. The new species differs from all other Neotropical congeners by its uniformly brown dorsal surface and the shape of medial lobe. The dorsal habitus and male genitalia are illustrated, and a distribution map is provided. The habitat, a small stream and associated forest pool, is illustrated and described. In addition, a new record of H. devexus Trémouilles, 1996, previously known from a single specimen, is reported from the highlands of northeastern Brazil, and a modified key to Neotropical species of the genus is provided.

Burmese amber reveals a new stem lineage of whirligig beetle (Coleoptera: Gyrinidae) based on the larval stage.

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.

Ultraconserved element (UCE) probe set design: Base genome and initial design parameters critical for optimization.

Targeted capture and enrichment approaches have proven effective for phylogenetic study. Ultraconserved elements (UCEs) in particular have exhibited great utility for phylogenomic analyses, with the software package phyluce being among the most utilized pipelines for UCE phylogenomics, including probe design. Despite the success of UCEs, it is becoming increasing apparent that diverse lineages require probe sets tailored to focal taxa in order to improve locus recovery. However, factors affecting probe design and methods for optimizing probe sets to focal taxa remain underexplored. Here, we use newly available beetle (Coleoptera) genomic resources to investigate factors affecting UCE probe set design using phyluce. In particular, we explore the effects of stringency during initial design steps, as well as base genome choice on resulting probe sets and locus recovery. We found that both base genome choice and initial bait design stringency parameters greatly alter the number of resultant probes included in final probe sets and strongly affect the number of loci detected and recovered during in silico testing of these probe sets. In addition, we identify attributes of base genomes that correlated with high performance in probe design. Ultimately, we provide a recommended workflow for using phyluce to design an optimized UCE probe set that will work across a targeted lineage, and use our findings to develop a new, open-source UCE probe set for beetles of the suborder Adephaga.

Tip-dated phylogeny of whirligig beetles reveals ancient lineage surviving on Madagascar.

The temporal origin of Madagascar's extraordinary endemic diversity is debated. A preference for Cenozoic dispersal origins has replaced the classical view of Mesozoic vicariance in the wake of molecular dating. However, evidence of ancient origins is mounting from arthropod groups. Using phylogenetic 'tip-dating' analysis with fossils, we show that a whirligig beetle species, Heterogyrus milloti, inhabiting forest streams in southeastern Madagascar is the last survivor of a once dominant and widespread Mesozoic group. With a Late Triassic to Early Jurassic origin (226-187 Ma) it is the hitherto oldest dated endemic lineage of animal or plant on Madagascar. Island biotas' sensitivity to extinction is well known, but islands can also provide refuge from continental extinction. Heterogyrus milloti is an irreplaceable link to the freshwater biota of the Mesozoic and serves as a reminder of what may be lost without critical conservation efforts on Madagascar.

Larval description and chaetotaxic analysis of Dineutus sinuosipennis Laporte, 1840, with a key for the identification of larvae of the tribe Dineutini (Coleoptera, Gyrinidae).

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.

The New World whirligig beetles of the genus Dineutus Macleay, 1825 (Coleoptera, Gyrinidae, Gyrininae, Dineutini).

All New World members of the whirligig beetle genus Dineutus Macleay, 1825 are treated. The New World Dineutus are found to be composed of 18 species and 6 subspecies: one species, Dineutusmexicanus Ochs, 1925, stat. n. is elevated from subspecies to species rank, and the subspecies Dineutuscarolinusmutchleri Ochs, 1925, syn. n. is synonymized here with the typical form. Lectotypes are designated for Dineutusdiscolor Aubé, 1838, Dineutesmetallicus Aubé, 1838, Dineutussolitarius Aubé, 1838, Dineutesanalis Régimbart, 1883, and Gyrinuslongimanus Olivier, 1795. Each taxonomic unit is provided with a taxonomic history, type locality, diagnosis, distribution, habitat information, and a discussion section. The aedeagus and male mesotarsal claws are illustrated, and dorsal and ventral habitus images of both sexes, for each species and subspecies are provided. General distribution maps are provided for all taxonimc units. A key to the genera of New World Gyrinidae, as well as all the New World Dineutus species is provided. General Dineutus anatomy as well as a clarification of homology and anatomical terms is included.

ResumenLas especies del Neuvo Mundo de género Dineutus Macleay, 1825 son revisadas. En el Neuvo Mundo Dineutus se compone de 18 especies y seis subespecies, la subespecie Dineutusmexicanus Ochs, 1925, stat. n. se eleva al rango de especie, y la subespecie Dineutuscarolinusmutchleri Ochs, 1925, syn. n. es sinonimizada con la forma típica. Lectotípos son designados por Dineutusdiscolor Aubé, 1838, Dineutesmetallicus Aubé, 1838, Dineutussolitarius Aubé, 1838, Dineutesanalis Régimbart, 1883, y Gyrinuslongimanus Olivier, 1795. Cada especie es acompañada de una diagnosis, historia taxonómica, tipo de hábitat que ocupa y una breve discusión. El edeago y uña metatarsal del macho son ilustrados, así como imágenes del habitus dorsal y ventral de ambos sexos. Se presentan mapas de distribución por especie, así como una clave para las especies del Neuvo Mundo de género Dineutus y los géneros de Gyrinidae del Neuvo Mundo. Características anatómicas de Dineutus y una clarificación de la homología de términos anatómicos son incluidos.

Revision of the Neotropical burrowing water beetle genus Liocanthydrus Guignot (Coleoptera: Noteridae: Noterinae: Noterini) with the description of two new species.

The burrowing water beetle genus Liocanthydrus Guignot, 1957 is redefined and its species are revised. Of the four current species, three are recognized as belonging to the genus and redescribed: L. angustus (Guignot, 1957), L. octoguttatus (Zimmermann, 1921) and L. uniformis (Zimmermann, 1921). The fourth species, L. buqueti (Laporte, 1835) is found to not be a member of Liocanthydrus, but of an undescribed genus. The noterid genus Siolius J. Balfour-Browne, 1969, is synonymized with Liocanthydrus (new synonymy) based on comparison of type specimens in both groups. Two of the three species described in Siolius, S. bicolor J. Balfour-Browne, 1969 and S. clayae J. Balfour-Browne, 1969, are recognized as valid, transferred to Liocanthydrus, and redescribed. The third, S. amazonicus J. Balfour- Browne, 1969, is synonymized with L. uniformis (new synonymy). Two new species from South America, L. armulatus sp. n. and L. nanops sp. n. are also recognized and described. A lectotype is designated for Canthydrus octoguttatus Zimmermann, 1921. After this revision, there are seven valid species of Liocanthydrus. Habitus photos are provided, diagnostic characters of all recognized species are illustrated, distributions are provided, and a key to the species is included.

On the family- and genus-series nomina in Gyrinidae Latreille, 1810 (Coleoptera, Adephaga).

All available genus- and family- group nomina for the Gyrinidae (Coleoptera: Adephaga) are listed along with original citation, original and current status, type nominal taxon with method of designation, and known synonymies and incorrect subsequent spellings. The nomina included follow the most current classification. Discussion is provided clarifying numerous nomenclatural problems with original spellings, correct authorship and type designation. Dineutini Ochs, 1926 syn. nov. is found to be a junior homonym of Dineutini Desmarest, 1851, and Enhydrini Régimbart, 1882 syn. nov. and its justified emendation Enhydrusini (Anonymous 2012) are here synonymized with Dineutini Desmarest, 1851.