Stigmella sanmartini Remeikis & Stonis, sp. nov. (Figs 1, 49–59) Type material. Holotype: ♂, ARGENTINA, Neuquen Province, San Martin de los Andes, elevation ca. 640 m, 29.ix.1981, Nielsen & Karsholt, genitalia slide no. RA 385♂ (ZMUC). Paratypes: 4 ♂, same locality, 20.ix–15. xi.1981, Nielsen & Karsholt, genitalia slide RA 329♂, RA 599♂, RA 637♂ (ZMUC); 1 ♂, same locality, 14.x.1981, mine on Mutisia decurrens Cav. (Asteraceae), Nielsen & Karsholt, genitalia slide no. RA 387♂ (ZMUC). Diagnosis. The combination of a phallus with two large cornuti, angular transtilla without sublateral processes, gnathos with two rather short caudal processes, wide and short lateral lobes of uncus, very short vinculum, and a golden glossy, grey-brown forewing with an ill-defined postmedian silvery fascia distinguishes S. sanmartini sp. nov. from all other Stigmella, including a few described and undescribed species which trophically are associated with Asteraceae plants and also possess only two cornuti in the male genitalia (also see Discussion). Male (Figs 49, 50). Forewing length 3.0– 3.2 mm; wingspan 6.7–7.1 mm. Head: palpi grey cream to grey; frontal tuft brown-grey to grey; collar and scape brownish cream to golden cream; antenna longer than half the length of forewing; flagellum with 42–43 segments, dark brown-grey, glossy. Thorax and tegula dark grey-brown with strong golden gloss; forewing grey-brown with golden gloss (dark grey at a certain angle of view); fascia of forewing subapical, ill-defined (usually narrow, indistinctive, and therefore sometimes hardly visible, only occassionally wide), comprised of silvery shiny scales; fringe dark grey, sometimes with areas of greyish white; underside of forewing brown-grey, without spots. Hindwing brownish grey to pale grey on upper side and underside, without spots or androconia; fringe brownish grey. Legs pale grey, silvery glossy to dark brownish grey. Abdomen grey on upper side, shiny grey on underside; genital segments grey cream to cream; anal tufts short, grey cream to grey. Female. Unknown. Male genitalia (Figs 55–59). Capsule longer (305 µm) than wide (170 µm). Uncus (Fig. 57) with two short but wide lobes. Gnathos with two rather short caudal process. Valva 185–190 µm long, 55–60 µm wide, with two small apical processes (Fig. 56); transtilla (Fig. 55) angular, without sublateral processes. Vinculum small triangular lateral lobes and very short ventral plate. Phallus (Figs 58, 59) 220–225 µm long, 80 µm wide; vesica with two cornuti: 50–75 µm long spine-like cornutus and 95–105 µm long horn-like cornutus. Bionomics (Figs 52–54). Host-plant: Mutisia decurrens Cav. (Asteraceae). Larva mines in leaves in October (and probably earlier). Leaf-mine (Figs 52–54) starts as a very slender sinuous gallery with interrupted very slender central line of black frass; further in the gallery widens; black frass fills ½ to 1/3 of the width of the widened gallery. Larval exit slit on upper side of the leaf. Adults fly from late September to November. Distribution (Figs 1). This species occurs in the southern Andes (Argentina: Neuquen Province) at altitudes about 650 m. Etymology. Despite the name of the type locality of Stigmella sanmartini sp. nov. (San Martin de los Andes), the species is named not after the locality, but in honor of Argentine general José de San Martín (1778–1850). A national hero of Argentina and Peru, he played a significant role in the southern part of South America's successful struggle for independence from the Spanish Empire.

Published as part of Stonis, Jonas R., Remeikis, Andrius, Diškus, Arūnas & Megoran, Nick, 2017, New species of leaf-mining Nepticulidae (Lepidoptera) from the Neotropical and Ando-Patagonian regions, with new data on host plants, pp. 1-39 in Zootaxa 4272 (1) on pages 12-17, DOI: 10.11646/zootaxa.4272.1.1, http://zenodo.org/record/583341