Bruno Clarkson

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

Abstract 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.

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.

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.

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.

A new species and records of Helochares (Insecta: Coleoptera: Hydrophilidae) from Southeastern Brazil

A new species of Helochares Mulsant, 1844 (Hydrophilidae: Acidocerinae) from Brazil is described and illustrated. Helochares (s. str.) atlanticus sp. nov. is distinct mainly by characteristics of the aedeagus whose phalobase is short, narrowed on basal third; parameres are thick, constricted on apical quarter, with small tooth-like projection on outer margin near apex; dorsal lobe longer than ventral lobe, shorter than parameres, very wide at base, abruptly narrowing toward apex until about half of its length where it dilates and divides into two long and narrow projections apart from each other at base, but turned inward at apex; ventral lobe acuminate and symmetrical. The rounded emargination on anteromedial margin of labrum bearing small tooth-like projections and the convex and slightly elevated mesoventral process, without high-elevated carina, also helps in identifying the species. Specimens of the new species were collected in the mountain region of the state of Rio de Janeiro (municipality of Teresopolis) and in the north coast of the state of Sao Paulo (municipality of Ubatuba), both localities in Southeastern Brazil. Helochares (s. str.) oculatus Sharp, 1882 and Helochares (Sindolus) femoratus (Brulle, 1841) are recorded for the first time from the state of Rio de Janeiro.