Pentoffia santosi sp. nov.

(Fig. 23–32, 41–44)

Diagnosis. Crown (Fig. 43) pale yellow with a narrow dark macula near anterior margin. Aedeagus (Figs 29–32) with pair of long and slender dorsally curved atrial processes, subequal in length to shaft; shaft approximately tubular and dorsally curved.

Description. Measurements (mm). Total length of holotype 7.7. Total length of paratypes 8.1−8.3.

Coloration. Pale yellow (Fig. 41, 42). Crown (Figs 43, 44) with a narrow dark macula near anterior margin; crown and frons with irregular orangish-yellow areas. Forewing hyaline white (Fig. 18) with smoky marginal area at apex. Legs (Figs 41, 42) pale yellow.

External morphology. Same as described for genus by Dietrich (2004).

Male terminalia. Pygofer (Fig. 25) longer than high; macrosetae distributed only on posterior third; apex concave. Subgenital plate (Fig. 25) almost extending to pygofer apex; in ventral view (Fig. 26), subtriangular, apex rounded. Connective (Fig. 27) with short arms, stem expanded apically. Style (Figs 27, 28) with apophysis short and stout; apex hooked on inner side and with distinct short spine on outer side. Aedeagus (Figs 29–32) with pair of long and slender atrial processes, strongly curved dorsally, subequal in length to shaft; shaft approximately tubular, in caudal view expanded laterally at midlength, in lateral view curved dorsally, apical third slightly expanded ventrally forming pair of small rugose flaps; apex, in dorsal view (Fig. 32), rounded.

Material examined. Male holotype, “ Peru, Cusco, 3 rd Km E\ Quincemil \ 13°13’03”S, 70°43’40”W \ 633m, 20.VIII–01.IX.2012, light\ A.P.M.Santos & D.M.Takiya ”, (MUSM) . Paratypes: 1 male and 1 specimen without abdomen, “ Peru, Cusco, Puente \ Inambari \ 13°10’53”S, 70°23’06”W \ 365m, 19.VIII.2012, light\ A.P.M.Santos & D.M.Takiya ”, (DZRJ and MUSM).

Etymology. The new species name is in honor of a friend, Prof. Dr. Allan Paulo Moreira dos Santos, a Brazilian trichopterologist who was one of collectors of the type series.

Notes. P. santosi sp. nov. is similar to P. nigra Dietrich, 2004 in the tubular and dorsally curved aedeagal shaft and shape, length, and curvature of the atrial processes. However, P. santosi sp. nov. differs from P. nigra by: (1) having the inverted Y-shaped macula on crown; (2) aedeagus atrial processes that do not cross each other and not twisted apically; and (3) aedeagus shaft with median region expanded laterally.