Smicridea (Rhyacophylax) dentisserrata sp. nov.

Figs 19–25

Adult male. Forewing length 3.7–4.0 mm (n = 7). Color in alcohol yellow. Antennae and legs light yellow. Forewings yellow, except those areas with transversal veins, nigma and thyridial spots brown and pterostigma dark, with white transverse subapical band, followed by brown distal band (Fig. 19). Anterolateral glandular processes of sternum V slender and long (0.92 mm), twice as long as this segment (Fig. 20).

Male genitalia: Segment IX forming triangular projection posteriorly, separated from tergum X by indentation in lateral view (Fig. 21); in dorsal view, posterior, lateral margins sclerotized, anterior margin narrowing dorsomesally, forming pointed projection covered by dark spikes (Fig. 22). Tergum X with sclerotized lateroventral margins and acute apex in lateral view; in dorsal view apex truncated, divided mesally its full length; ventral margins each with process expanded laterally and posteriorly, each with its external margin and apex with small spines in dorsal and lateral views (Figs 21, 22). Inferior appendages 2-segmented; basal segment long with distal region enlarged, covered with long setae; distal segment short and narrow, about 2/5 as long as basal segment, apically blunt in dorsal and lateral views (Figs 21, 22). Phallus with tubular phallobase, basal section large; basal and median sections forming angle of approximately 135o; median section with distinct dorsal cap at mid length (Fig. 21), cap margin, in dorsal view, with asymmetrical pointed projections (Figs 23, 24); 2 triangular paramere spines apicoventrally, with anterior one ending in 7 points and posterior one bare and apically broad and truncate in ventral and lateral views (Figs 21, 24, 25), dorsal dark region (Figs 21, 25); internal sclerotized portion of ejaculatory duct, in lateral view, slender and elongated (about ½ phallus length) (Fig. 21); in dorsal view, divided in 2 parts apically (Figs 23, 24); everted phallus with median region, phallicata, expanded, bearing 2 short, sclerotized, lateral processes (Fig. 23), these processes internal in retracted phallus (Figs 24, 25); dorsal periphallic membranes absent.

Female and immatures. Unknown.

Diagnosis. The male of S. dentisserrata sp. nov. differs from those of the other species described in the subgenus by having tergum X bearing a pair of sclerotized processes expanded laterally and posteriorly, their external margins and apices bearing small spines, by having the 2 apicoventral triangular paramere spines of the phallobase triangular in shape, and the endophalic membranes with an expanded region with 2 short, sclerotized, lateral processes. The male is similar to those of S. (R.) pseudolobata Flint 1978 and S. roraimense sp. nov. by having a distinct dorsal cap on the phallotheca at mid length, but differs from both species by having this cap apically acute.

Biology: Specimens of S. dentisserrata sp. nov. were collected with light traps placed over streams and rivers (n = 3) with width between 2.5 and 55 m, with preserved gallery forest in the Cerrado biome.

Distribution. Brazil, Mato Grosso State.

Etymology. The name dentisserrata (Latin, denti = a tooth and serrati = a saw), refers to the serrated edge of the internal margin of tergum X, which has small teeth, observed in the males of this species.

Material examined. Holotype male: BRAZIL, Mato Grosso, Nova Xavantina municipality, Córrego da Mata (2nd order stretch), S 14º59'18" W 52º27'30"; 25.x.2005, H. S. R. Cabette, light trap with mercury lamp over white cloth, 1 male [alcohol] (INPA). Paratypes: BRAZIL, Mato Grosso, Nova Xavantina municipality, Córrego da Mata (2nd order stretch), S 14º59'18" W 52º27'30"; 25.x.2005, H.S.R. Cabette, light trap with mercury lamp over white cloth, 39 males [alcohol] (INPA); (4th order stretch), S 15º01'32" W 52º26' 29; 17.ix.2005, light trap with mercury lamp over white cloth, H.S.R. Cabette, 2 males [alcohol] (UNEMAT); 2 males [alcohol] (MZUSP); 11 males [alcohol] (INPA); Barra do Garças municipality, Rio Pindaíba (6th order stretch), S 14º54'10" W 52º00'21", 15.xi.2005, H.S.R. Cabette, light trap with mercury lamp over white cloth, 5 males [alcohol] (INPA).