New species and new records of Notonecta ( Hemiptera : Heteroptera : Notonectidae ) from Brazil

Notonecta itatiaia sp. nov. is described from the state of Rio de Janeiro. Like other Notonecta species that occurs in Brazil, N. itatiaia has no remarkable diagnostic features than the shape of genital capsule. Along with the first description of a Notonecta from Brazil in eighty years, N. disturbata is newly recorded from the states of Pará, Piauí and São Paulo, and N. pulchra from Pará. A key to species of Notonecta (males) occurring in Brazil is given.

Notonecta Linnaeus, 1758 is a cosmopolitan genus with about 65 species (TRUXAL 1979), and is one of the four genera of the tribe Notonectini (ŠTYS & JANSSON 1988).Individuals of this genus are mid-sized notonectids, with a maximum body length of 16 mm, being smaller than Enithares Spinola, 1837 and Enitharoides Brooks, 1953.Members of Notonecta have the pronotum with lateral margins not foveate, median femur stout with anteapical pointed protuberance, and genital capsule symmetric.They are found in lentic waters with moderate to high abundance of submerged plants (LÓPEZ RUF et al. 2003).Some species prefer shady places under bushes whereas others are found on open waters (HUNGERFORD 1933).
According to MOREIRA et al. (2011), seven species of Notonecta occur in Brazil: N. bifasciata Guérin-Méneville, 1844, N. disturbata Hungerford, 1926, N. polystolisma Fieber, 1851, N. pulchra Hungerford, 1926, N. nigra Fieber, 1851, N. sellata Fieber, 1851and N. variabilis Fieber, 1851.The last three species have no other records in Brazil since their descriptions.Most of the records of Notonecta from Brazil are restricted to the southeastern region of the country, where three species are more commonly found: N. polystolisma, N. disturbata and N. pulchra (NIESER & MELO 1997, VIANNA & MELO 2003, SOUZA et al. 2006, RIBEIRO et al. 1998, 2010).Since the revision of Notonecta made by HUNGERFORD (1933), no other species of the genus has been described from Brazil.In this work a key to the species that occur in Brazil is provided, including a new species, along with new records from the country.

MATERIAL AND METHODS
Specimens are deposited in the Coleção Entomológica Prof. José Alfredo Pinheiro Dutra, Departamento de Zoologia, Instituto de Biologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro (DZRJ) and Instituto Nacional de Pesquisas da Amazônia, Manaus (INPA).In quotations of label data, a comma separates different information and a semicolon separates information of different specimens.An exclamation mark (!) indicates new records of a species.Collectors are cited in parentheses.The full citation of individual specimens collected at the same locality on different dates is not given.The letter "m" refers to male specimens and the letter "f" to female ones.All localities are listed geographically from north to south.
Measurements were made with an ocular micrometer on a stereoscopic microscope and are given in millimeters.Morphological terms follow HUNGERFORD (1933).The dissected genital structures are stored in microvials with alcohol.In the absence of N. nigra, N. sellata, N. variabilis and N. bifasciata specimens, their illustrations were based on HUNGERFORD (1933) Hemelytra dark brown with claval suture delimited by a yellow stripe, a short yellow stripe below, and a dimmed yellow stain before membrane (Figs 9 and 10).Legs entirely yellow except coxae brown.Dorsal and ventral surface of abdomen brown.Connexivum yellow.Head.Vertex a little longer than its anterior width; slightly longer than rear margin of an eye and more convex than anterior margin of eye.Synthlipsis wide, about one-half of width of anterior margin of vertex and a little longer than one-half rear margin of an eye.Thorax.Pronotum width 1.6 times its longitudinal median length; length about 1.6 times longitudinal length of head; posterior margin straight with oblique extremities anterad.Scutellum distinctly longer than pronotum.Membranal lobes of hemelytra equal.Anterior trochanter with a hook at lateral margin.Mesotrochanter rounded.Apex of metaxyphus V-shaped.Internal margin of hind femur slightly sinuous.Abdomen.Ventral keel not bare.Penultimate abdominal sternite with spatulated apex.Last abdominal sternite deltoid with truncated apex (Fig. 11).Genital capsule without digitate process, with caudoventral and posterior pointed protuberance and dorsal portion acute (Fig. 12).Clasper apex not bifurcate; slightly longer than dorsal portion of genital capsule; two-thirds of clasper length broad from base, tapering at apical third.
Etymology.The species epithet, itatiaia, refers to the locality (municipality of Itatiaia) in which the holotype was collected.
Remarks.In general, the species of Notonecta do not show many diagnostic features.Identification is performed through ratios between measures and by the shape of the genital capsule and clasper.The genital capsule of N. itatiaia has a conspicuous shape, with a posterior rounded protuberance, absent in other species.

New records
Notonecta disturbata Hungerford, 1926 Notonecta disturbata is a common species that occurs in Paraguay and Argentina (MOREIRA et al. 2011), and is also widely distributed in Brazil (see records below).This species shows substantial variation in color, with individuals entirely clear to individuals with most of the body dark and with some clear stains.
It is very similar to N. pulchra, with the same range of body length.They are better distinguished by the shape of the genital capsule.Notonecta disturbata has two caudoventral protuberances and the dorsal portion of the genital capsule is acute; N. pulchra has only one caudoventral protuberance and the dorsal portion of the genital capsule is rounded.