Anacroneuria piti sp. n.

Figs. 2A–2 D (male) and Figs. 3A–3 F (nymph).

Material examined. Holotype male (CZNC): Brazil (BRA), Espírito Santo State (ES), Alegre, Rio Norte, reared, nymph collected 07.viii.2004, emerged 08.viii.2004 .

Description. General color yellowish. Head yellowish with M-line not distinct, parts of clypeal area yellowish and frons light brown (Fig. 2A); lappets brown; clypeal area setose; post frontal line not distinct; scape and pedicel light brown; flagellomeres light brown; palpi light brown. Pronotum light brown with lighter rugosities (Fig. 2A).

Legs yellowish to light brown, tibia and tarsi darker. Wing membrane light brown with veins darker. Cerci light brown.

Male: Forewing length 11mm (n=1). Penial armature (Figs. 2 B–2D), in ventral view, gradually tapering from medially to apex and terminating in an indistinct small aperture (Fig. 2 C), with a pair of small distal membranous vesicles (Figs. 2 C–2D); in lateral view, pronounced keel apparent (Fig. 2 D), distinct in dorsal view appearing as two parallels bars (Fig. 2 B); hooks relatively short and flattened, little curved and with acute apices (Fig. 2 C).

Nymph: General color brownish. Head brown with lighter areas near post-frontal suture and in frontoclypeal region (Fig. 3A); M-line complete, distinct; eyes black and ocelli black with a darker stain medially. Pronotum brownish with median line and sparse areas yellowish (Fig. 3A). Mandibles, maxillae, and labium as in Figs. 3 B, 3C, 3D. Forefemur with lateral surface covered by scattered bristles (Fig. 3 E); dorsally and ventrally with higher density of thick bristles; dorsally with translucent fringe of hairs. Tibia ventrally with thin and sparse translucent bristles, and dorsally with a row of thick bristles in the border and a well-developed band of hairs. Cerci brown with thick bristles; segments differ in shape and size from base to apex (Fig. 3 E). Thoracic gills: ASC1, PSC1, AT2, AT3 and PT3 (sensu Shepard & Stewart 1983; Stewart & Stark 2002). Measurements (n=7): head width 2.9– 3.3 mm; head length 1.9–2.6 mm; antennae length 4.0–5.0mm; pronotum width 2.5–3 mm; pronotum length 1.5–2 mm; cercal length 6.5–7.5 mm; total length 7.9–9 mm.

Remarks. The color of the adult is similar to many species of the genus. The penial armature of A. pitii in ventral view (Fig. 2 C) and lateral view (Fig. 2 D) is most similar to A. itatiaiensis Baldin et. al 2013 also known from southeastern Brazil, but differs in the size of membranous vesicles and apex. In A. pitii, the vesicles are smaller and are more medially than in A. itatiaiensis . The penial armature (Figs. 2 B–2D) of A. pitii is more robust basally than A. itatiaiensis . In lateral view (Fig. 2 D), the apex of A. pitii is thinner than A. itatiaiensis; the hooks are more robust in A. piti . Furthermore the color of A. pitii is lighter than A. itatiaiensis .

Etymology. The patronym honors Pitágoras da Conceição Bispo, a Brazilian Plecoptera specialist.