Stigmella rigida Diškus & Stonis, sp. nov.

(Figs 18, 27, 29, 93–97)

Type material. Holotype: Ƌ, PERU, Dept. Ancash, 35 km SE Huaraz, Cerro Cahuish, 9°40'50"S, 77°13'32"W, 4100 m, Quabrada Pucavado, 15–18.ii.1987, O. Karsholt, genitalia slide no. AD625Ƌ (ZMUC).

Diagnosis. The combination of a U-shaped gnathos, five large, slightly curved cornuti, and speckled, nearly 5 mm long forewing distinguishes S. rigida sp. nov. from all other Stigmella species.

Male (Figs 93, 94). Forewing length about 4.8 mm; wingspan about 10.2–10.3 mm. Head: palpi cream, glossy; frontal tuft comprised of cream and fuscous grey piliform scales; collar cream, comprised of a few long lameral scales; scape cream with few pale grey-brown scales and brownish cream pecten; antenna slightly longer than half the length of forewing; flagellum with 49 segments, grey-brown. Thorax and tegula grey-brown, distally brownish cream. Forewing glossy cream, speckled with brown and dark brown scales; few brown scales with weak purple and blue iridescence; fascia absent; fringe pale brown; underside of forewing dark grey-brown with no spots or androconia. Hindwing pale brown to brownish cream on upper side and underside, with no spots or androconia; its fringe pale brown. Legs cream to brownish cream, darkened with grey-brown on upper side.

Female. Unknown.

Male genitalia (Figs 95–97). Capsule longer (510 µm) than wide (320 µm). Vinculum with triangular lateral lobes and long ventral plate. Uncus with two small narrow lobes (bent inwardly in fig. 96). Gnathos U-shaped, with slender transverse bar instead central plate. Valva slender, pointed apically, 330–335 µm long, 60–70 µm wide, with sharp apical processes; transtilla with short triangular sublateral processes. Juxta membranous, widening caudally. Phallus (Fig. 97) 380–395 µm long, 120–130 µm wide; vesica with a set of five large and very large, slightly curved and straight cornuti.

Bionomics. Adults fly in February. Otherwise biology unknown.

Distribution (Figs 18, 27). This species occurs high in the Peruvian Andes (Peru: Ancash Departamento) at altitudes about 4100 m.

Etymology. The species name is derived from Latin rigidus (hard, unflexible, unbending) in reference to the heavily hardened, or sclerotized, capsule and phallus in the male genitalia.