Description of Microvelia urucara sp . nov . and new distributional data on veliids ( Insecta : Heteroptera : Veliidae ) from the Amazon River floodplain , Brazil

Based on material collected on streams and lakes from the Amazon River floodplain, Brazil, Microvelia urucara sp. nov. is described, illustrated and compared with similar species. The new species, like many other Neotropical Microvelia Westwood, 1834, does not present striking modifications on the body or appendages, but can be separated from its congeners by features of the male genitalia. Distributional data is presented for other veliids collected along the Amazon River, and Paravelia capixaba Moreira, Nessimian & Rúdio, 2010 and Microvelia summersi Drake & Harris, 1928 are recorded for the first time from the Brazilian Amazon. Rhagovelia jubata Bacon, 1948 is newly recorded from the state of Amazonas, and Microvelia mimula White, 1879, M. pulchella Westwood, 1834 and M. venustatis Drake & Harris, 1933 are recorded for the first time from the state of Pará.

Wings surpassing genital segments.Fore wings with four closed cells, two proximal and two distal.Legs relatively thin, without spines, tubercles, or modified groups of setae.Fore tibia widened distally.Mid femur at most as thick as hind femur.
Type-material.BRAZIL, Amazonas: Urucará, Lírio do Vale, Lago do Albano, U. Distribution.Microvelia urucara sp.nov.has been collected exclusively with light traps, near lakes and a stream from the Amazon River floodplain; no specimens have been collected in association with the hydrophytes sampled.The distributional range of this species along the Amazon River is of more than 1,500 km.
Etymology.This species is named after the municipality of Urucará, state of Amazonas, where the holotype was collected.
Remarks.The flattened ventral side of the relatively long second genital segment (Fig. 3) separates M. urucara sp.nov.from other Neotropical Microvelia, except for Microvelia costaiana Drake & Hussey, 1951 from Rio de Janeiro.The second genital segment is ventrally convex on the vast majority of species occurring in Tropical America, a feature that can be easily observed by placing the genital segments in lateral view.Besides being flattened, the second genital segment of M. urucara sp.nov. is projected on the posterolateral angles, a condition that is not common among Neotropical Microvelia.Both M. urucara sp.nov.and M. costaiana lack any conspicuous modification of the body and legs; tubercles and spines are absent.Based on the original description, both species can be separated by the color pattern, the head with a pair of broad yellowish stripes, legs dark fuscous-brown and venter of abdomen bluish-black in M. costaiana, whereas the head is entirely yellow or brown, legs are mostly yellow and abdomen brown in M. urucara sp.nov.They can also be separated by the shapes of the posterior margin of last abdominal sternite and of the dorsum of abdominal segment I, which are both truncate in M. costaiana, and concave in M. urucara sp.nov.Finally, specimens of M. urucara sp.nov.are distinctly shorter than those of M. costaiana, macropterous individuals of the first species are about 1.6 mm long, whereas apterous of the second are 2.0 mm long.Based on the drawing provided in the original description, M. cavernula Polhemus, 1972, from Venezuela, might have a flattened second genital segment, but this characteristic has not been mentioned in the description itself, or in the diagnosis of the species.The second genital segment is also relatively long, but lacking the posterolateral projections seen in M. urucara sp.nov.The shape of the last abdominal sternite also separates the two species, only M. cavernula bearing a deep posterior excavation.
Among the species cited above, only two had not yet been recorded from the Brazilian Amazon: P. capixaba and M. summersi.Paravelia capixaba was reported in 2010 from the state of Espírito Santo, Brazil, and no other records have been published then since.We acknowledge that the records presented here are very far from the type-locality.However, after comparing our exemplars with the types, including detailed analysis of the male proctiger and parameres, we are confident that they represent the same species.Microvelia summersi had been recorded from "Brazil" by DRAKE & HUSSEY (1955), but the record did not include further details.The species is also known from Grenada, Trinidad & Tobago, Panama and Guyana, and its occurrence in Northern Brazil was not unexpected.
In addition to these new records, R. jubata is recorded for the first time from the state of Amazonas, and M. mimula, M. pulchella and M. venustatis are recorded for the first time from the state of Pará.
Table II.Distribution of the Veliidae collected along the Amazon River floodplain, Brazil.Material collected on streams or lakes near the main sampling sites are marked by an exclamation mark.New records are displayed by "+" sign on the last three columns.

Table I .
Location, date and coordinates of the collecting stations along the Amazon River floodplain, Brazil.