A review of the Oocyclus Sharp of Ecuador with description of 12 new species (Coleoptera: Hydrophilidae: Laccobiini)

The species of the hygropetric water scavenger beetle genus Oocyclus Sharp, 1882 are reviewed for Ecuador. The genus has not previously been reported from the country. Twelve new species are described: O. ancho sp. n., O. ankas sp. n., O. bellus sp. n., O. kichwa sp. n., O. lepidus sp. n., O. packha sp. n., O. radiatus sp. n., O. rupestris sp. n., O. sumak sp. n., O. ustulatus sp. n., O. yantzaza sp. n., and O. zamora sp. n. One previously described species is newly reported for Ecuador: O. sharpi Short & Perkins 2004. There is at least one additional species that is part of a species complex that includes O. morgani García-Hernández, 2009 from Colombia and O. trujillo Short & García, 2010 from Venezuela. One new synonymy is proposed: the Venezuelan species O. zulianus Short & García, 2010 syn. n. is placed as a junior subjective synonym of O. sharpi Short & Perkins, 2004. A key to all described species known from the Andes region of South America is provided.

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.

Protosternini (Coleoptera : Hydrophilidae) corroborated as monophyletic and its larva described for the first time: a review of the myrmecophilous genus Sphaerocetum

The genus Sphaerocetum Fikáček, 2010 is reviewed on the basis of specimens collected from mixed ant nests shared by Camponotus Mayr, 1861 and Crematogaster Lund, 1831 ants in Peninsular Malaysia. Two new species, S. arboreum, sp. nov. and S. hortulanum, sp. nov., are described. A larva of S. arboreum was collected in the same nest as the adults, implying that it is likely that the entire life cycle takes place inside the ant nest; its association with adults was confirmed by cox1 sequences. It is described in detail and represents the first known larva of the tribe Protosternini. Fragments of four genes (cox1, cox2, 18S and 28S) were amplified for S. arboreum and combined with previously generated data in order to test the position of the genus within the subfamily Sphaeridiinae. The analyses revealed Sphaerocetum as a sister taxon to Protosternum Sharp, 1890, corroborating the monophyly of the tribe Protosternini. Bayesian analysis revealed an alternative hypothesis of the phylogenetic position of the tribe, indicating that Protosternini is a sister-group to Omicrini. This position is supported by the chaetotaxy of the maxillary stipes of the larva, which lacks the increased number of stout setae on the inner face present in all other Sphaeridiinae larvae except Omicrini.

Clade age and diversification rate variation explain disparity in species richness among water scavenger beetle (Hydrophilidae) lineages

Explaining the disparity of species richness across the tree of life is one of the great challenges in evolutionary biology. Some lineages are exceptionally species rich, while others are relatively species poor. One explanation for heterogeneity among clade richness is that older clades are more species rich because they have had more time to accrue diversity than younger clades. Alternatively, disparity in species richness may be due to among-lineage diversification rate variation. Here we investigate diversification in water scavenger beetles (Hydrophilidae), which vary in species richness among major lineages by as much as 20 fold. Using a time-calibrated phylogeny and comparative methods, we test for a relationship between clade age and species richness and for shifts in diversification rate in hydrophilids. We detected a single diversification rate increase in Megasternini, a relatively young and species rich clade whose diversity might be explained by the stunning diversity of ecological niches occupied by this clade. We find that Amphiopini, an old clade, is significantly more species poor than expected, possibly due to its restricted geographic range. The remaining lineages show a correlation between species richness and clade age, suggesting that both clade age and variation in diversification rates explain the disparity in species richness in hydrophilids. We find little evidence that transitions between aquatic, semiaquatic, and terrestrial habitats are linked to shifts in diversification rates.

A revision of the Lutrochidae (Coleoptera) of Venezuela, with description of six new species

The species of Lutrochidae occurring in Venezuela are revised. The only previously recorded species, Lutrochus acuminatus Grouvelle, is redescribed and a lectotype is designated. Lutrochus vestitus Sharp, is recorded from Venezuela and French Guiana for the first time. Six new species Lutrochus gustafsoni n. sp., L. cauraensis n. sp., L. maldonadoi n. sp., L. meridaensis n. sp., L. minutus n. sp., and L. violaceus n. sp. are described. Notes on habitat and habits for most species are provided, as well as a key to the eight species of Lutrochidae occurring in Venezuela. The family is reported from hygropetric habitats for the first time.

Ciimaerocyon gen. nov., a morphologically aberrant myrmecophilous genus of water scavenger beetle (Coleoptera: Hydrophilidae: Sphaeridiinae)

Anew hydrophilid genus Chimaerocyon gen. nov. containing two species, C. shimadai sp. nov. (Malaysia: Pahang) and C. sumatranus sp. nov. (Indonesia: Sumatra), is described. Specimens of C. shimadai were collected from brood cells in anest of Pheidole singaporensis Özdikmen, 2010. The biology of C. sumatranus remains unknown. A molecular phylogeny based on four genes (cox1, cox2, 18S and 28S) supports the placement of the genus as deeply nested within the Cercyon-group of the tribe Megasternini. This position is supported by the subdistal position of the median spur in the hind wing (unique to Megasternini) and the presence of sucking disc on male maxilla (unique for Megastemini+Sphaeridiini). The remaining external morphology differs substantially from other representatives of Megasternini. The hypothesis that the aberrant morphology of Chimaerocyon gen. nov. is a consequence of myrmecophily is discussed.

Review of the Berosus Leach of Venezuela (Coleoptera, Hydrophilidae, Berosini) with description of fourteen new species

The species of the water scavenger beetle genus Berosus Leach occurring in Venezuela are reviewed. Thirty-six species are recorded, including fifteen new species, fourteen of which are described here as new: Berosus araguasp. n., Berosus asymmetricussp. n., Berosus capanaparosp. n., Berosus castaneussp. n., Berosus corozosp. n., Berosus ebeninussp. n., Berosus garciaisp. n., Berosus humeralissp. n., Berosus jolyisp. n., Berosus llanensissp. n., Berosus megaphallussp. n., Berosus ornaticollissp. n., Berosus repertussp. n., and Berosus tramidrumsp. n. The fifteenth new species, known from a single female, is left undescribed pending the collection of males. Twelve species are recorded from Venezuela for the first time: Berosus ambogynus Mouchamps, Berosus consobrinus Knisch, Berosus elegans Knisch, Berosus geayi d'Orchymont, Berosus ghanicus d'Orchymont, Berosus guyanensis Queney, Berosus holdhausi Knisch, Berosus marquardti Knisch, Berosus olivae Queney, Berosus reticulatus Knisch, Berosus wintersteineri Knisch, and Berosus zimmermanni Knisch.

Discovery of the water scavenger beetle genus Brownephilus Mouchamps in Turkey (Coleoptera, Hydrophilidae, Hydrophilini

The recently described Hydrochara major İncekara, Mart, Polat, & Karaca, 2009 from Turkey is transferred to the genus Brownephilus Mouchamps. New records and habitat information are given for the species, as well as diagnostic features for separating it from the only other described member of the genus, Brownephilus levantinus Balfour-Browne. The discovery of Brownephilus in Turkey marks the first time the lineage has been found since its original description more than seventy years ago.