Journal of Natural History Vol. 46, Nos. 11–12, March 2012, 717–727 Description and notes on the bionomics of a new species of Potamophilops Grouvelle, 1896 (Coleoptera: Elmidae: Larainae), from the Cerrado biome in Brazil André Silva Fernandes a,b * and Neusa Hamada c a Institut de Biologia Evolutiva (IBE, CSIC-UPF), Passeig Maritim de la Barceloneta 37-49, Barcelona, 08003 Spain; b Capes Foundation, Ministry of Education of Brazil, CEP: 70040-020, Brasília-DF, Brazil; c Instituto Nacional de Pesquisas da Amazônia, Coordenaç¯ ao de Biodiversidade, Manaus, Brazil (Received 8 March 2011; final version received 17 December 2011; printed 8 February 2012) Potamophilops bragaorum sp. nov. is described and illustrated based on adult speci- mens collected in a mountainous area in the Cerrado biome in Taquaruçú district, Tocantins state, Brazil. This is the second species described in the genus and it represents the northernmost record of Potamophilops, which is known only from Argentina and Brazil. In this article we provide a diagnosis, details on the mor- phology and images of the habitus and structures used to determine the species and to distinguish the gender. Field observations permitted the description of some aspects on the biology of the new species that seem to be very similar to those of other Larainae genera. Examination of gut contents revealed a diet based mostly on periphyton. Keywords: aquatic insects; riffle beetles; taxonomy; Cerrado biome; Neotropics Introduction Grouvelle (1896) created the genus Potamophilops to include the species Potamophilus cinereus Blanchard, 1841, because he considered that this species had character- istics that were not found in any previously known Larainae genus. The type species was then, Potamophilops cinereus (Blanchard, 1841), which was the only known species in the genus (Spangler and Santiago 1987). In their revision of some Neotropical Larainae genera, Spangler and Santiago (1987) presented a diagnosis for Potamophilops and a detailed description and illustrations of P. cinereus. The genus was known only from Argentina (Corrientes province) and Brazil (Mato Grosso do Sul state and São Paulo state) (Blanchard 1841; Spangler and Santiago 1987; Vanin and Costa 2011) (Figure 1). Based on Spangler and Santiago (1987) and on examination of specimens of the new species, Potamophilops can be distinguished from all other Larainae genera by the following combination of features: body elongated, densely pubescent; body length more than 5.0 mm; labrum very broad, wider than clypeus; antennae widely sepa- rated at base, each antenna with 11 segments; pronotum wider than long, narrowed anteriorly, with deep and complete anterior transversal impression, posterolateral *Corresponding author. Email: andrelmis@gmail.com ISSN 0022-2933 print/ISSN 1464-5262 online © 2012 Taylor & Francis http://dx.doi.org/10.1080/00222933.2011.651643 http://www.tandfonline.com Downloaded by [André Fernandes] at 02:04 09 February 2012