Stigmella torosa Remeikis & Stonis

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, Zootaxa 4272 (1), pp. 1-39 : 20-24

Stigmella torosa Remeikis & Stonis , sp. nov.

( Figs 1 , 84–88 )

Type material. Holotype: ♂, ARGENTINA, Río Negro Province, San Carlos de Bariloche, Colonia Suiza, elevation ca. 800 m, 23.xi.1981, Nielsen & Karsholt, genitalia slide no. RA 291♂ ( ZMUC) . Paratype: 1 ♀, same locality, 3.xii.1981, Nielsen & Karsholt, genitalia slide no. RA 303♀ ( ZMUC) .

Other material examined (not type series; see Remarks): 1 ♀, ARGENTINA, Río Negro Province, San Carlos de Bariloche, Camino del Tronador, elevation ca . 800 m, 29.xi.1978, Mision Cientifica Danesa, genitalia slide RA309♀ (ZMUC); 1 ♀, Colonia Suiza, elevation ca . 800 m, 23.xi.1981, Nielsen & Karsholt, genitalia slide no. RA318♀ (ZMUC).

Diagnosis. The combination of an unique set of cornuti in the phallus (see fig. 88), angular transtilla, large lateral lobes of vinculum, and a wide golden glossy postmedian fascia distinguishes S. torosa sp. nov. from all other Stigmella species, including the most similar S. hylomaga (Meyrick) and S. monstrata sp. nov.

Male ( Figs 84, 85 ). Forewing length about 2.6 mm; wingspan 5.7 mm. Head: palpi brownish cream; frontal tuft fuscous brown in frons, whitish beige on vertex; collar small, yellowish cream; scape cream; flagellum greybrown with strong golden gloss on upper side and underside. Thorax and tegula grey-brown with golden gloss. Forewing: grey-brown with golden gloss, dark reddish brown with golden gloss but without purple iridescence on apical third (beyond fascia); fascia postmedian, silvery shiny; fringe brownish grey to pale grey with some overlapping silvery scales; underside of forewing grey-brown, without spots. Hindwing brownish grey to greybrown on upper side and underside, without spots or androconia; its fringe grey-brown. Legs silvery brownish to grey-brown. Abdomen grey, shiny on upper side and underside.

Female. Similar to male. Forewing length 2.3–2.4 mm; wingspan 5.1–5.2 mm. Flagellum with 33–34 segments.

Male genitalia ( Figs 86, 88 ). Capsule longer (335 µm) than wide (255 µm). Uncus with four caudal papillae. Gnathos with two stout caudal processes. Valva 185–200 µm long, 90–95 µm wide, with two small apical processes; transtilla rather angular, without sublateral processes. Vinculum with large lateral lobes. Phallus ( Fig. 88 ) 250–315 µm long, 125 µm wide; vesica with 5 very large cornuti.

Female genitalia ( Fig. 87 ). Total length about 985 µm. Anterior and posterior apophyses almost equal in length. Vestibulum with a paired vaginal sclerite. Corpus bursae with large folded part and 380 µm long, 435 µm wide basal part, with pectination; signa absent. Accessory sac short but wide; ductus spermathecae with one sclerite. Abdominal apex gradually narrowed, rounded distally.

Bionomics. Adults fly in November–early December. Otherwise biology unknown.

Distribution ( Figs 1 ). This species occurs in the southern Andes ( Argentina: Rio Negro Province) at altitudes around 800 m.

Etymology. The species name is derived from Latin torosus (brawny) in reference to the strongly developed set of stout cornuti comprised of large and very large cornuti.

Remarks. Some, rather insignificant differences in morphology have been observed in two studied females (slides RA309 and RA318); most likely these females slightly differ from the female paratype RA303 because a morphological variation of the species (not because they belong to different species), nevertheless these two females were not included in the type series.

Figures

FIGURE 1. Distribution map to the species treated in the current paper.

FIGURES 84 – 88. Stigmella torosa Remeikis & Stonis, sp. nov. 84, 85, male adult, holotype; 86, male genitalia, capsule with phallus removed, genitalia slide no. RA 291; 87, female genitalia, slide no. RA 303; 88, male genitalia, phallus, genitalia slide no. RA 291 (ZMUC).