Stigmella epicosma ( Meyrick, 1915 )

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 : 11

1. Stigmella epicosma ( Meyrick, 1915)

( Figs 2 , 9 , 33 , 37 )

Nepticula epicosma Meyrick, 1915: 255 .

Stigmella epicosma (Meyrick) ; Davis 1984: 18.

Stigmella epicosma (Meyrick) ; Puplesis & Robinson 2000: 28 (and only figs 20, 99–101).

Material examined. PERU: 1 ♂ [designated in Puplesis & Robinson 2000], Lima, 150 m [500 ft], 12°03'41"S, 77°01'41"W, viii.1914, Parish, genitalia slide no. 28849 ( BMNH) (see Remarks).

Diagnosis. Belongs to the S. schoorli group. The combination of a brown scaling of forewing’s base, very short lateral lobes of vinculum, and two almost equally large horn-like cornuti (rate: 1:1.2; the longer cornutus twice exceeds the width of phallus) distinguishes S. epicosma from the most resembling members of the group ( S. alticosma and S. paracosma sp. nov.). From similar S. schoorli and S. hamata , S. epicosma may be easily distinguished by the the shiny median fascia of forewing and rounded inner lobe of valva.

Male ( Fig. 33 ). Described in Puplesis & Robinson 2000: 28. Wingspan: about 4.1 mm.

Female. Unknown (see Remarks).

Male genitalia. Illustrated in Puplesis & Robinson 2000: figs 99–101 (figs 102, 103 were incorrectly identified and assigned to S. epicosma ; they belong to S. paracosma Remeikis & Stonis , sp. nov.).

Bionomics. The species was reported by Vargas (2011) on native shrubs of Trixis cacalioides (Kunth) D. Don , Asteraceae , growing in the coastal valleys of northern Chile and Peru. Larvae mine in August and December. Cocoon cream white ( Vargas 2011). Adults fly in August and December.

Distribution ( Fig. 9 ) This species occurs in Peru (Lima) at altitudes about 150 m; recently it was also recorded from two coastal valleys in the desert of northern Chile, Arica Province ( Vargas 2011).

Remarks. In the S. epicosma material, Puplesis & Robinson (2000) also 1 ♀ paralectotype (from Lima, genitalia slide no. 28850, BMNH) and 7 ♂ and 2 ♀ non-type series specimens (from Arequipa and Oyón , both Peru) were listed. The authors reported that all specimens in a series from 2920 m in Arequipa have a distinct glossy silver basal fascia, one male specimen collected at 4000 m in Oyón has the basal area of the forewing glossy gold, a fuscous-gold shiny collar and greyish white palpi; additionally, the left cornutus in the phallus of this specimen from Oyón is half the length of that in the lectotype from Lima . It was expected that the observed differences in wing coloration and observed differences of genital structures may represent a geographical variation in the mountainous, dissected terrain where the specimens were collected. However, our recent re-examination of these similar specimens has not confirmed the attribution of all listed specimens to S. epicosma and we have reassigned them to different species: from Arequipa (including genitalia slide nos Diškus186, Diškus187 ZMUC, illustrated in Puplesis & Robinson: figs 102, 103) are attributed to S. paracosma Remeikis & Stonis , sp. nov.; from Oyón (genitalia slide no. Diškus 188 ZMUC, illustrated in Stonis et al. 2016d: figs 174–179) are attributed to S. alticosma Remeikis & Stonis ; the paralectotype ♀ specimen (genitalia slide no. 28850 BMNH, illustrated in Puplesis & Robinson: fig. 211) is identified as an undescribed species, probably of Enteucha Meyrick.

Figures

FIGURE 33. 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.