Stigmella inca Diškus & Stonis, 2017

Stonis, Jonas R., Diškus, Arūnas, Remeikis, Andrius, Karsholt, Ole & Torres, Nixon Cumbicus, 2017, Illustrated review of the leaf-mining Nepticulidae of the central Andes (Peru and Bolivia), Zootaxa 4257 (1), pp. 1-70 : 39-41

31. Stigmella inca Diškus & Stonis , sp. nov.

( Figs 2 , 9 , 12, 15 , 35 , 65–71 , 105 )

Type material. Holotype: ♂, PERU: Huamanga Province , 9 km East of Ayacucho (Muyurina), 13°06'52˝S, 74°11'47˝W, elevation 2510 m, mining larva on Sida sp. 29.x.2008, ex pupa xi.2008, field card no. 4956, A. Diškus, genitalia slide no. AD 755♂ ( ZMUC) . Paratypes: 2 ♂, 1 ♀, same label data as holotype, genitalia slides nos AD699♂, AD725♂, AD762♀ (ZMUC); 7 ♂, 11 ♀, ECUADOR, Loja Province, Vilcabamba , 4°17'45˝S, 79°12'59˝W 1940 m, larvae on Sida sp. 23.i.2017, A. Diškus ( ZMUC) .

Diagnosis. Belongs to the S. nivea species group. The combination of differentiated band of cornuti into clusters of size-wise different spines, short arms of transtilla, and simple shaped but broad plate of gnathos distinguishes S. inca sp. nov. from all members of the S. nivea group, including the most similar species ( S. nivea and S. eiffeli ). Externally, S. inca sp. nov. may be easily distinguished from the possibly most closely related S. nivea by the distinctly speckled forewing and absence of grey-white scales on forewing apex.

Male ( Fig. 35 ). Forewing length 2.0– 2.8 mm; wingspan 4.4–6.2 mm. Head: palpi cream to yellowish cream; frontal tuft pale beige or comprises of yellowish cream, blackish grey and brown-grey piliform scales; collar cream to yellowish cream, divided distally; scape yellowish cream; antenna longer than half the length of forewing; flagellum with 33–34 segments, dark grey-brown on upper side, grey-cream on underside. Thorax, tegula and forewing yellowish cream to pale grey, densely speckled with brown and black-brown scales; these dark scales with some or without purple iridescence; fringe cream to grey cream apically, pale grey on tornus; underside of forewing dark grey-brown, without spots. Hindwing grey to pale grey on upper side and underside, without spots or androconia; its fringe grey. Legs dark grey-brown on upper side, brownish cream on underside. Abdomen browngrey to grey on upper side, cream, glossy on underside; genital plates cream; anal tufts pale brown to grey, very distinctive and long (as long as the width abdominal apex).

Female ( Fig. 35 ). Forewing length about 2.8 mm; wingspan about 6.2 mm. Flagellum with 32 segments. Abdomen dark grey on upper side, yellowish cream on underside; ovipositor very slender; anal tufts pale grey, very distinctive and long (almost as long as the length of ovipositor).

Male genitalia ( Figs 65–71 ). Capsule significantly longer (285–290 µm) than wide (165 µm). Uncus bilobed. Gnathos with one large caudal process and simple shaped plate. Valva 185–190 µm long, 40–45 µm wide, with two slender and sharp apical processes; transtilla with very short arms and without sublateral processes. Juxta membranous. Vinculum with small pointed lateral lobes, and short ventral plate. Phallus ( Fig. 66 ) 325–350 µm long, 80–95 µm wide; vesica with few clusters of size-wise different cornuti gathered into a large band.

Female genitalia ( Fig. 105 ). Total length 915 µm. Anterior and posterior apophyses almost equal in lenght; anterior apophyses blunt distally; posterior apophyses very slender. Vestibulum narrow, without sclerites. Corpus bursae with long folded distal part and large, 290 µm long, 310 µm wide basal part; pectinations comb-like; signa absent. Accessory sac very large, heavily folded; ductus spermathecae with 0.5 convolution. Abdominal apex tapered into long and slender ovipositor.

Bionomics ( Figs 126–130 ). Larva mines in leaves of Sida L. ( Malvaceae : Malvoideae ) ( Fig. 126 ). Larva pale to greenish yellow, with indistinctive intestine and brown head; mines in October. Leaf-mine ( Figs 127–130 ) starts as very slender sinuous gallery with a wide, sometimes interrupted central line of black frass; then gallery abruptly widens to a blotch with irregularly scattered brown-black or green-black frass. Larval exit slit on upper side of the leaf. Cocoon brownish white; length 2.6–3.0 mm, maximum width 1.2–1.4 mm.

Distribution ( Figs 9 , 15 ). This species occurs in the Andes (southern Ecuador and Peru: Huamanga Departamento) at altitudes about 1940–2500 m ( Figs 12, 15 ).

Etymology. This species is named after the Inca people, the Andean civilization.

Figures

FIGURE 35. Adults of the central Andean Nepticulidae.

FIGURES 1 – 8. Distribution of the central Andean Nepticulidae. 1, high-Andean species recorded at altitudes above 3700 m (after Stonis et al. 2016 d); 2, species recorded at altitudes below 3700 m; 3 – 8, some collecting areas in the Peruvian Andes.

FIGURES 9 – 11. Distribution of the central Andean Nepticulidae. 9, species recorded at altitudes below 3700 m; 10, 11, some collecting areas in Peru. * — Stigmella epicosma Meyrick is also known from Arica Province, northern Chile (Vargas 2011); ** – S. inca sp. nov. is also discovered in southern Ecuador.

FIGURES 12 – 18. Distribution of some central Andean Nepticulidae. 12 – 14, 17, 18, habitats, Peru; 15, 16, distribution maps.

FIGURES 65 – 71. Male genitalia of Stigmella inca Diškus & Stonis, sp. nov., holotype, genitalia slide no. AD 725 (ZMUC); 65, general view; 66, phallus; 67, 69 – 71 capsule; 68, valva.

FIGURES 104 – 107. Female genitalia of new Stigmella species. 104, S. acalyphae Diškus & Stonis, sp. nov., paratype, genitalia slide no. AD 756; 105, S. inca Diškus & Stonis, sp. nov., paratype, genitalia slide no. AD 762; 106, S. coronaria Diškus & Stonis, sp. nov., paratype, genitalia slide no. AD 769; 107, same, genitalia slide no. AD 771 (ZMUC).

FIGURES 126 – 130. Stigmella inca Diškus & Stonis, sp. nov. 126, host-plant, Sida spp.; 127, 128, leaf-mines from Peru; 129, 130, leaf-mines from southern Ecuador.