Ancient relicts or recent immigrants? Different dating strategies alter diversification scenarios of New Zealand aquatic beetles (Coleoptera: Hydrophilidae: Berosus).

Dated species-level phylogenies are crucial for understanding the origin and evolutionary history of modern faunas, yet difficult to obtain due to the frequent absence of suitable age calibrations at species level. Substitution rates of related or more inclusive clades are often used to overcome this limitation but the accuracy of this approach remains untested. We compared tree dating based on substitution rates with analyses implementing fossil data by direct node-dating and indirect root-age constraints for the New Zealand endemic Berosus water beetles (Coleoptera: Hydrophilidae). The analysis based solely on substitution rates indicated a Miocene colonization of New Zealand and Pleistocene origin of species. By contrast, all analyses that implemented fossil data resulted in significantly older age estimates, indicating an ancient early Cenozoic origin of the New Zealand clade, diversification of species during or after the Oligocene transgression and Miocene-Pliocene origin of within-species population structure. Rate-calibrated time trees were incongruent with recently published Coleoptera time trees, the fossil record of Berosus and the distribution of outgroup species. Strong variation of substitution rates among Coleoptera lineages, as well as among lineages within the family Hydrophilidae, was identified as the principal reason for low accuracy of rate-calibrated analyses, resulting in underestimated node ages in Berosus. We provide evidence that Oligocene to Pliocene events, rather than the Pleistocene Glacial cycles, played an essential role in the formation of the modern New Zealand insect fauna.

A new species of Chasmogenus Sharp, 1882 and new records of Hydrophilidae (Coleoptera) from Northeastern Brazil.

Chasmogenus cajuina sp. nov., a new species of the water scavenger beetle (Hydrophilidae: Acidocerinae) is described and illustrated, based on adult males, collected in the Lower Parnaíba River Basin, north of Piauí, Northeast Region of Brazil. In addition, Helochares (Sindolus) femoratus (Brullé, 1841) and Hydrobiomorpha spatula Bachmann, 1988 are recorded from Piauí State for the first time.

Cercyon Leach, 1817 (Coleoptera: Hydrophilidae: Sphaeridiinae) from Brazil: new species and records

Abstract The study of ca. 280 specimens of Cercyon Leach, 1817 (Hydrophilidae: Sphaeridiinae: Megasternini) deposited in the Coleção Entomológica Pe. J.S. Moure, Universidade Federal do Paraná, Brazil, revealed a new species from Atlantic Rain Forest biome in Paraná State (Southern Brazil) and new records. Cercyon (Cercyon) curi sp. nov. is herein described and illustrated, belonging to the Neotropical C. variegatus species group. Cercyon (Cercyon) nigriceps (Marsham, 1802) is recorded for the first time in Paraná State, and Cercyon (Cercyon) inquinatus Wollaston, 1854 from Amazonas State (Northern Region); these records extend the distributional range of both species in Brazil. Cercyon (Cercyon) praetextatus (Say, 1825) is recorded for the first time from Brazil based on specimens collected in Paraná. Those three species were previously recorded as introduced in South America.

Two new species of the water scavenger beetle genus Hemiosus Sharp Coleoptera: Hydrophilidae) from Colombian Andes.

Two new species of Hemiosus (Coleoptera: Hydrophilidae) from the central cordillera of the Colombian Andes are described. Hemiosus molanoi González-Rodríguez García-Hernández sp. nov. and H. quindiensis González-Rodríguez Clarkson sp. nov. are described based in 56 adult specimens collected in river-associated sandy puddles (26 specimens of H. molanoi sp. nov.) and temporary puddles near crops (26 specimens of H. quindiensis sp. nov.). Both species are identified mainly by characteristics of the aedeagus: Hemiosus molanoi sp. nov. has subtriangular parameres, median lobe shorter than parameres and longer than appendices which are acuminate and phallobase shorter than parameres, strongly asymmetrical in basal two-fifths; H. quindiensis sp. nov. has parameres gradually tapering towards rounded apices, median lobe shorter than parameres and longer than appendices which are acuminate and phallobase shorter than parameres, strongly asymmetrical in basal half. Dorsal coloration pattern, overall shape of the meso- and metaventral process and abdominal ventrites are also informative to distinguish the new species from remaining described Hemiosus. Diagnoses, illustrations and habitat characteristics are provided.

On the genus Berosus Leach (Coleoptera: Hydrophilidae) in the State of Roraima, Brazil: description of three new species and new records.

As a contribution to knowledge of the aquatic beetles of the Neotropical Region, the genus Berosus Leach is recorded for the first time from Roraima State in northern Brazil. Three new species are described and illustrated: Berosus illuviosus sp. n., B. parvus sp. n., and B. andreazzei sp. n. In addition, we present a checklist of the Berosus species collected in 26 ponds in the savanna area of the State of Roraima, with 12 new species records for the state, five of which are also new country records for Brazil.

A new species and new records of Oocyclus Sharp, 1882 (Coleoptera: Hydrophilidae) from Brazil.

A new species of Oocyclus Sharp, 1882, O. pilosus sp. nov. is described and illustrated from Mato Grosso State in Central-Western Brazil. Oocyclus itapecum Clarkson Short 2012 and O. yubai Clarkson Short 2012 are newly recorded from São Paulo and from Mato Grosso, Goiás and Paraná States respectively. The doubtful record of Oocyclus aeneus Clarkson Short 2012 in Mato Grosso State is herein confirmed. An updated key to the Brazilian species of Oocyclus is provided.

A new species of Phaenostoma d'Orchymont, 1937 (Coleoptera: Hydrophilidae) from Brazil.

A new species of Phaenostoma d'Orchymont, 1937 (Hydrophilidae: Sphaeridiinae: Coelostomatini) from Brazil is des-cribed and illustrated. Phaenostoma tupiniquim sp. nov. is described based on an adult male specimen from the Caatinga biome in Ceará State (Northeastern Brazil) and two specimens from uncertain localities, but most likely Mato Grosso and Pará States (Central-western and Northern Brazil, respectively). An updated key to the five known species is provided.

Aquatic Insects from the Caatinga: checklists and diversity assessments of Ubajara (Ceará State) and Sete Cidades (Piauí State) National Parks, Northeastern Brazil.

BACKGROUND: Diversity and distribution of Neotropical aquatic insects is still poorly known, with many species to be recorded and many others to be described, due to the small number of taxonomists and sparse faunistic studies. This knowledge is especially poor in the Caatinga Domain in Northeastern Brazil, even though, this region may have played an important historical role in the spatial evolution of faunas of forested areas in northern South America. NEW INFORMATION: Aquatic insect checklists of 96 species from Parque Nacional de Ubajara (Ceará State, Brazil) and 112 species from Parque Nacional de Sete Cidades (Piauí State, Brazil) are presented, representing the following taxa: Elmidae, Epimetopidae, Hydrophilidae, and Torridincolidae (Coleoptera), Hemerodromiinae (Diptera: Empididae), Ephemeroptera, Gerromorpha and Nepomorpha (Hemiptera), Odonata, Plecoptera, and Trichoptera. Because of the scarce number of biological inventories in Northeastern Brazil, several new distributional records (of species, genera, and families) for Brazil, Northeastern Brazil, and Ceará and Piauí states are provided. In addition, several undescribed species were detected, being 26 from Ubajara and 20 from Sete Cidades. Results represent a significant increase to the known fauna of these states, ranging from 13%-70% increase for Ceará and 41% to 91% increase for Piauí. Although both parks are relatively close to each other and within the Caatinga domain, their aquatic fauna display a very high complementarity (89% species), possibly due to structural differences of water bodies sampled in each park. Rarefaction curves based on quantitative light trap samples suggest a much higher expected species richness of aquatic insects at Sete Cidades than at Ubajara National Park. Discussion on biogeographical affinities of this sample of the Caatinga fauna is provided.

On Brazilian Helobata Bergroth, 1888 (Coleoptera: Hydrophilidae): description of two new species, new records, and key to species.

Two new species of Helobata Bergroth, 1888 (Hydrophilidae: Acidocerinae) from Brazil are described and illustrated. Helobata amazonensis sp. nov. is described based on an adult male specimen from the Amazon River floodplains, Amazonas State. Helobata pantaneira sp. nov. is described based on an adult male specimen collected from swamps in the Pantanal biome, in Mato Grosso State. Helobata corumbaensis Fernández & Bachmann, 1987, H. larvalis (Horn, 1873) and H. quatipuru Fernández & Bachmann, 1987 are recorded for the first time from Mato Grosso; Amazonas, Ceará and Mato Grosso; and Rio de Janeiro States respectively. Diagnosis, illustrations, a checklist and a key to Brazilian species of Helobata are provided.

Four new species and first nominal record of Chasmogenus Sharp, 1882 (Coleoptera: Hydrophilidae) from Brazil.

The genus Chasmogenus Sharp, 1882 (Hydrophilidae: Acidocerinae) is recorded from Brazil for the first time. Four new species are described and illustrated from the Southeastern Region of the country: C. fluminensis sp. nov. (Rio de Janeiro State), C. lilianae sp. nov. (Rio de Janeiro State), C. itatiaia sp. nov. (Minas Gerais and Rio de Janeiro States), and C. ubatuba sp. nov. (São Paulo State). Chasmogenus sapucay Fernández, 1986 is recorded for the first time from Northern and Southeastern Brazil. Notes on morphology and an updated key for the South American species are provided.