Stigmella polylepiella Diskus & Stonis 2016

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).