Stigmella polylepiella Diškus & Stonis, 2016

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 : 28

13. Stigmella polylepiella Diškus & Stonis, 2016

( Figs 2 , 9, 11 , 13, 15 , 32 , 37 , 121–124 )

Stigmella polylepiella Diškus & Stonis, in Stonis et al. 2016e: 86 –90, figs 7–26.

Material examined. 2 ♂ (holotype and paratype), PERU, 60 km NW of Cuzco, Ollantaytambo , 13°15'31"S, 72°15'54"W, elevation about 2850 m, mining larvae on Polylepis racemosa Ruiz & Pav. , 21.x.2008, field card no. 4948, A. Diškus, genitalia slide nos AD739 (holotype), AD741 (paratype) ( ZMUC).

Diagnosis. The combination of the densely speckled forewing with some golden gloss and purple iridescence, closely juxtaposed processes of gnathos, three-lobed uncus, and unique set of cornuti in the phallus distinguishes S. polylepiella from all other Stigmella species; the host-plant Polylepis racemosa (Rosaceae) also makes this species distinctive.

Male ( Fig. 32 ). Described in Stonis et al. 2016e: 86, figs 14–17. Forewing length about 2.6 mm; wingspan 5.7–5.8 mm.

Female. Unknown.

Male genitalia. Illustrated in Stonis et al. 2016e: figs 22–26.

Bionomics ( Figs 121–124 ). Larvae mine in leaves in October. Host-plant: Polylepis racemosa Ruiz & Pav. (Rosaceae) . Egg beige cream, mat (lustreless), oval-shaped, flattened dorso-ventrally, attached (not glued) on the leaf under side. Leaf-mine starts as a narrow gallery filled with black frass; later it develops abruptly to a large blotch with frass irregularly scattered but most of it remains accumulated in basal part of the blotch ( Fig. 121 ). Larva spins its cocoon inside the mine; the mine swells and becomes blisterlike at this stage ( Fig. 124 ). Cocoon purplish brown to purplish dark brown; shape of the cocoon unusual, narrow; length 2.0– 2.4 mm, maximal width 0.8–0.83 mm ( Fig. 123 ). Exit slit on upper side of the leaf. Using our ‘Formula of Evaluation of Abundance and Occurrence of Leaf-miners’ (see Diškus, Stonis 2012: 52–54), Stigmella polylepiella is extremely abundant in the type locality: a mass mining of the new species were observed (sometimes with a few leaf-mines on a single leaf); more than 300 leaf-mines with larvae were collected at a single site in Ollantaytambo, Peru ( Figs 13, 15 ).

Distribution ( Figs 9 ,). This species occurs in the Andes ( Peru: NW of Cuzco) at altitude about 2850 m ( Fig. 11 ).

Figures

FIGURE 32. Adults of the central Andean Nepticulidae.

FIGURE 37. Diagnostics of the central Andean Stigmella.

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 116 – 125. Leaf-mines of Nepticulidae species. 116 – 120, Acalyptris murex Diškus & Stonis, sp. nov., host-plant Collaea speciosa (Loisel.) DC.; 119, 120, same, leaf-mines; 121 – 124, leaf-mines and cocoon of S. polylepiella Diškus & Stonis, 2016 on Polylepis racemosa Ruiz Lopez & Pavon (after Stonis et al. 2016 e); 125, leaf-mine of unknown Stigmella taxon on Polylepis racemosa Ruiz Lopez & Pavon (after Stonis et al. 2016 e).