Stigmella robusta Remeikis & Stonis

Stonis, Jonas R., Diškus, Arūnas, Remeikis, Andrius, Gerulaitis, Virginijus & Karsholt, Ole, 2016, Leaf-mining Nepticulidae (Lepidoptera) from record high altitudes: documenting an entire new fauna in the Andean páramo and puna, Zootaxa 4181 (1), pp. 1-94 : 41

Stigmella robusta Remeikis & Stonis , sp. nov.

( Figs 18 , 27 , 103–107 )

Type material. Holotype: Ƌ, PERU, Dept. Ancash, 35 km SE Huaraz, Cerro Cahuish, Quabrada Pucavado , 9°40'50"S, 77°13'32"W, elevation ca. 4100 m, 15–18.ii.1987, O. Karsholt, genitalia slide no. RA566Ƌ ( ZMUC) . Paratypes: 3 Ƌ, 3 ♀, same label data as holotype, genitalia slide nos RA575Ƌ, RA576Ƌ, RA580♀ (ZMUC).

Diagnosis. The combination of a gnathos with closely juxtaposed processes, angular inner lobe of valva, large, distally four-lobed uncus, set of 2–3 large cornuti and cluster of small spine-like cornuti, and pale, speckled forewing distinguishes S. robusta sp. nov. from all other Stigmella species.

Male ( Fig. 103 ). Forewing length 3.5–4.5 mm; wingspan 7.6–9.6 mm. Head: palpi cream; frontal tuft ochre cream; collar and scape yellowish cream; antenna as half the length of forewing; flagellum with 42 segments, yellowish grey to grey. Thorax and tegula yellowish cream (concolorous with collar and scape). Forewing glossy yellowish cream speckled with ochre-brown to dark ochre-brown scales (sometime with little purple iridescence); fascia absent; fringe grey cream to yellowish grey; underside of forewing ochre-brown to dark brown, with cream basal spots but no androconia. Hindwing pale grey to grey on upper side and underside, with no spots or androconia; its fringe yellowish grey. Legs yellowish cream, darkened with dark metalic grey on upper side. Abdomen fuscous grey on upper side, grey cream to pale brownish on underside; tufts short, pale grey to grey; genital segments cream to grey cream.

Female. Similar to male.

Male genitalia ( Figs 104–106 ). Capsule longer (325 µm) than wide (175 µm). Vinculum with long triangular lateral lobes and very long ventral plate. Uncus wide, with four small lobes distally. Gnathos with two slender, closely juxtaposed caudal processes. Valva 175–180 µm long, 54–60 µm wide, with two distinctive apical processes and prominent (conspicuous) angular inner lobe; transtilla with triangular corners (instead sublateral processes). Juxta membranous, indistinctive. Phallus ( Fig. 104 ) 280–285 µm long, 70 µm wide; vesica with two to three large cornuti and basal cluster of numerous small slender cornuti.

Female genitalia ( Fig. 107 ). Total length 1140–1155 µm. Anterior processes slender; posterior apophyses slightly longer, very slender. Vestibulum narrow, without sclerites. Corpus bursae with heavily folded distal part and round, 500–505 µm long, 500 µm wide basal part with comb-like pectinations; signa absent. Accessory sac wide but short; ductus spermathecae with 4.5 convolutions. Abdominal tip narrowed and rounded.

Bionomics. Adults fly in February.

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 robustus (stout, strong) in reference to the heavily hardened (sclerotized) uncus, large angular inner lobe of valva and large, strongly sclerotized vinculum in the male genitalia.

Figures

FIGURE 27. Distribution map of the high-Andean Nepticulidae with height records.

FIGURES 18 – 19. Distribution of high altitude Nepticulidae and collecting in the Peruvian Andes. 18, distribution map; 19, collector and co-author Ole Karsholt in Polylepis forest during Polylepis Expedition organized by Prof. Dr. Jon Fjeldså (the leader of the Polylepis Expeditions, ZMUC) in 1987.

FIGURES 103 – 107. Stigmella robusta Remeikis & Stonis, sp. nov. 103, male adult, holotype; 104, male genitalia, holotype, genitalia slide no. RA 566, phallus; 105, same, capsule without phallus; 106, same, dorsal view of capsule; 107, female genitalia, paratype, genitalia slide no. RA 580 (ZMUC).