Megacraspedus cottiensis, Huemer & Karsholt & Wieser, 2020

Huemer, Peter, Karsholt, Ole & Wieser, Christian, 2020, Megacraspedus cottiensis sp. nov. (Lepidoptera, Gelechiidae) from northern Italy - a case of taxonomic confusion, ZooKeys 963, pp. 141-152 : 141

Megacraspedus cottiensis sp. nov. Figures 2-3 , 4 , 7

Type material.

Holotype. Italy; • ♂; prov. Torino, Parco Naturale N Orsiera - Rocciavrè, Fenestrelle, ca. 0.7 km NE Pequerel; 45°3'6"N, 7°4'16"E; 1820 m; 29 Jun. 2019; leg. P. Huemer; [Barcode identification number] TLMF Lep 27447; [genitalia slide number] GEL 1299 ♂ P. Huemer; coll. TLMF (Fig. 2 ).

Paratypes.

Italy; • 39 ♂, 2 ♀; same data as holotype; 1 ♂; [Barcode identification number] TLMF Lep 27448; 1 ♀; [Barcode identification number] TLMF Lep 27446; [genitalia slide number] GEL 1300 ♀ P. Huemer; coll. TLMF; • 31 ♂, 2 ♀; same data as holotype; 23 Jul. 2019; coll. TLMF; • 10 ♂; same data as holotype; leg. C. Wieser; coll. LMK; • 7 ♂; prov. Torino, Parco Naturale N Orsiera - Rocciavrè, Via Colle delle Finestre, Forte Serre Mariae E; 45°2'58.88"N, 7°3'5.29"E; 1840 m; 30 Jun. 2019; leg. C. Wieser; coll. LMK; • 1 ♂; prov. Torino, Valsusa, Mompantero, Monte Rocciamelone; 2200 m; 3 Jul. 1993; leg. G. Bassi; genitalia prep. (in glycerin); coll. ZMUC [misidentified paratype of M. neli ]; • 1 ♂; same data, but loc. Riposa; 2200 m; 16 Jul. 1993, leg. G. B. Delmastro; coll. TLMF [misidentified paratype of M. neli ]; • 5 ♂; prov. Torino, Parco Naturale Orsiera - Rocciavrè, Usseaux, Colle delle Finestre N, 45°4'21"N, 7°3'11"E; 2180 m; 24 Jul. 2019; leg. P. Huemer; coll. TLMF; • 14 ♂; prov. Torino, Parco Naturale Gran Bosco di Salbertrand, 2 km SE Colle dell´Assieta; 45°3'38"N, 6°58'44"E; 2240 m; 25 Jul. 2019; leg. P. Huemer; coll. TLMF; • 5 ♂; prov. Torino, Parco Naturale Gran Bosco di Salbertrand, 1.8 km SE Colle dell´Assieta; 45°3'40"N, 6°58'21"E; 2350 m; 21 Jul. 2020; leg. P. Huemer; coll. TLMF.

Diagnosis.

Megacraspedus cottiensis belongs to a group of species with three distinct black spots in the forewing. It is characterised by the dark basal part of the costa and the dark grey-brown costal area of the forewing in the males, but otherwise it is very similar to other species of the M. faunierensis species group. This species is also similar to M. tristictus Walsingham, 1910 and M. pentheres Walsingham, 1920 in external appearance.

Major diagnostic characters are found in the male genitalia (Figs 4-6 ). The male genitalia of M. cottiensis differs from that of M. neli by the slightly narrower uncus, the long lateral sclerites of the saccus exceeding the maximum width of the saccus, and the slender phallus. The new species is easily separated from M. faunierensis by the smaller, less triangular-shaped saccus with proportionally longer lateral sclerites, and several other subtle characters such as the proportionally larger uncus, and more slender valva and phallus.

The female genitalia differ from that of M. faunierensis by the convex anterior projection of the subgenital plate and the transverse, suboval signum whereas characters such as the differing lengths and widths of the ductus and corpus bursae may be variable (Figs 7 , 8 ). The female genitalia are similar to those of several other species of Megacraspedus and the documented characters generally seem of limited diagnostic value in the delimitation of species.

Finally, all species are easily separated by DNA barcode sequences (Fig. 1 ).

Description.

Adult. Male (Fig. 2 ). Forewing length 4.0-5.8 mm. Segment 2 of labial palpus with moderately long scale brush, brown on outer surface, white mottled with brown on inner surface, white on lower and upper surface; segment 3 creamy white. Antennal scape without pecten; flagellum dark brown, at most weakly ringed with white. Head and thorax creamy white to cream. Forewing light yellowish brown, more or less intensively mottled with brown, costal half variably covered with grey-brown scales, dorsal half lighter, base of costa dark grey-brown, a black dot in fold at 2/5 and two black dots in middle of wing and at end of cell; some black-tipped scales along termen; fringes light grey. Hindwing light grey with concolourous fringes. Female (Fig. 3 ). Flagellum distinctly ringed with white. Head and thorax yellowish brown. Forewing length 4.1-4.2 mm. Forewing narrow, apically pointed, almost unicolourous light yellowish brown, without grey brown costal half, darker towards apex, fringes whitish. Hindwing lanceolate, whitish grey. Otherwise similar to male.

Variation. The extension of the darkened part of the costa as well as the amount of black scales on the forewings is variable.

Male genitalia (Fig. 4 ). Uncus moderately small, nearly sub-rectangular, apical corners rounded, apical edge with weak medial emargination; gnathos hook moderately slender, straight, apically pointed, approximately length of uncus; anterior margin of dorsal surface of tegumen with suboval emargination, sclerotised ridges from anterior edge converge in medial part of tegumen; pedunculi small, suboval, with small ridge; valva approximately width of uncus, stout, extending slightly beyond base of uncus, digitate distal part, apex broadly rounded; saccular area densely covered with setae, with longitudinal ridge, without separated sacculus; posterior margin of vinculum medially emarginated, with lateral humps, vincular sclerite elongated sub-ovate, with nearly straight sclerotised posterior edge; saccus moderately small, slightly shorter than valva, slender V-shaped, ratio maximum width to length 0.6, posterior margin with weak convex projections, separated by minute incision, medial part with sclerotised ridge from posterior margin to approximately middle, lateral sclerites approximately 1.3 times length of maximum width of saccus; phallus weakly curved at ca. one-third, with inflated coecum, two times wider than distal part, distal part 2.5 times length of coecum, sclerotised dorsal ridge, apex slender; ductus ejaculatorius with small internal sclerotisation.

Female genitalia (Fig. 7 ). Papilla analis small, apically rounded; apophysis posterior slender rod-like, ca. 2.5 mm long, with short, bifurcate posterior end, bordered by small sclerotised field; segment VIII long and slender, ca. 0.7 × 0.4 mm, largely membranous; subgenital plate with sub-triangular subostial sclerotisation, posteriorly weakly extended sclerites delimiting small ostium bursae, anterior margin with rod-like edge connected with apophysis anterior, medially with moderately short convex projection; apophysis anterior slender, rod-like, free-standing part approximately length of segment VIII, posteriorly becoming rod-like venula of segment VIII, extending to posterior margin of segment VIII; colliculum short; ductus bursae short, slender; corpus bursae, moderately short and slender, distinctly delimited from ductus bursae, entire length of ductus and corpus bursae ca. 1.7 mm; signum small, transverse, suboval spiny plate.

Distribution.

Northern part of the Cottian Alps in northwestern Italy.

Biology.

Host plant and early stages are unknown. Adults were collected from late June to late July in a xeromontane grassland (Fig. 9 ) at artificial light sources. Males were attracted in the first 3 hrs of the night, with females, discovered by lighting the vegetation with a headlamp. Specimens were collected at altitudes ranging from ca. 1800 to 2350 m.

Etymology.

The specific name is an adjective derived from the Cottian Alps, where the new species was discovered.

Molecular analysis.

Eight specimens of the Megacraspedus faunierensis species group, covering all three described species, were successfully sequenced (sequence length 599 to 658 bp). Intraspecific distances are generally low (not applicable for M. neli ), ranging from a minimum of 0% to a maximum of 1.71%, whereas interspecific divergence is much higher, ranging between 7.12 and 9.04% among members of the species group and 12.14% to the nearest species M. sumpichi Huemer & Karsholt, 2018 (Table 1 , Fig. 1 ) These values, however, are based on a low number of samples. All species in the group belong to different BINs ( Ratnasingham and Hebert 2013); the BIN ID for M. cottiensis is BOLD:AEA4020 (n = 3). All the individuals of the new species share the same haplotype and the distance to the nearest congeneric neighbour, M. faunierensis , is 9.04% (p-dist).

Figures

Figure 1. Neighbor-Joining tree (built with MEGA 7) of cytochrome c oxidase subunit I (COI) barcode fragments. Values on branches represent bootstrap values of ≥ 75 % inferred from 500 replicates, scale bar represents substitutions per site. Note: the scale bar only applies to internal branches between species. The width of the triangles represents the sample size, and the depth the relative genetic variation within the cluster (2 x scale bar). Source: DNA Barcode data from BOLD (Barcode of Life Database, cf. Ratnasingham and Hebert 2007).

Figure 9. Habitat of Megacraspedus cottiensis sp. nov., Parco Naturale Orsiera - Rocciavre, Forte Serre Mariae environs (photograph M. Vilgut).

Figures 2 - 3. Megacraspedus cottiensis sp. nov., adult. 2 male, holotype; 3 female, paratype. Scale bar: 2 mm, all to scale.

Figures 4 - 6. Male genitalia of Megacraspedus faunierensis species group. 4 M. cottiensis sp. nov., holotype; 5. M. neli, holotype; 6 M. faunierensis, paratype, genitalia slide GEL 1219. Scale bar: 200 µm, all to scale.

Figures 7 - 8. Female genitalia of Megacraspedus faunierensis species group. 7 M. cottiensis sp. nov., paratype, genitalia slide GEL 1300; 8 M. faunierensis, paratype, genitalia slide GEL 1235. Scale bar: 200 µm, all to scale.