Biston rosenbaueri, Mueller, Bernd, 2018

Mueller, Bernd, 2018, Bistonrosenbaueri sp. n. (Lepidoptera, Geometridae, Ennominae) from the Balkan Peninsula, Nota Lepidopterologica 41 (2), pp. 207-213 : 209-211

Biston rosenbaueri sp. n. Figs 1, 2, 5, 6.

Type material.

Holotype ♂, Ost-Griechenland [Eastern Greece], Thrakien [Thrace], Avantas, 29.ii.-01.iii.2016, leg. F. Rosenbauer, gen. prep. 1033 B. Müller, deposited in coll. ZSM; Paratypes:1 ♂, same data as holotype, not dissected, coll. FRM; 1 ♂, Kroatien [Croatia], Insel Krk, 4 km östl. Punat, 300 m a.s.l., 27.iii.2005 at light, E. Friedrich [leg.], gen. prep. 1030 B. Müller, coll. EFJ; 1 ♂, Kroatien [Croatia], Insel Krk, 3 km s/w, Vrbnik, 200 m a.s.l., 26.iii.2005 at light, E. Friedrich [leg.], gen. prep. 1032 B. Müller, coll. EFJ.2 ♂♂ Kroatien [Croatia], Insel Krk, 3 km s/w, Vrbnik, 200 m a.s.l., 26.iii.2005 at light, E. Friedrich [leg.], coll. EFJ, not dissected, 1 ♂ Greece, Florini , Kristalopigi, 1000 m, 17.iv.1987, Peder Skou leg., gen. prep. 015 Peder Skou, coll. PSS.

Adult male

(Figs 1, 2).Wingspan 40-45 mm. Abdomen, thorax, tegulae very hairy. Forewing: Ground colour white, densely suffused with light and dark brown, sometimes also black scales, together giving a pale grey or brownish impression. Veins brown or black. Postmedial and antemedial line distinct, black, on veins thickened, forming small triangles pointing towards the wing base. Postmedial line undulating, angled on vein M3 and M2. Antemedian line bent, sharp or more diffuse, sometimes angled on M3 and A. Medial line indistinct. Postmedial line on outer margin, antemedial line on inner margin with a broad pale brown band, in darker specimens indistinct. Terminal area with a diffuse whitish line, sometimes absent. Discal spot distinct, slightly blurry. It lies between the postmedial and the medial line. Hindwing less suffused with dark scales, therefore paler than the forewing. Its postmedial line nearly straight, its medial line diffuse, straight. Discal spot present as a distinct dot. Both wings with fringes weakly chequered brownish and grey. Labial palpi also very hairy, medium brown, frons rough-scaled, whitish. Patagia anteriorly whitish, posteriorly black. Tegulae whitish, irrorated with more or less black scales. Thorax greyish-brown as for tegulae. Abdomen beige and grey scaled. Antennae of males bipectinate with noticeable reddish-brown ciliated processes and variegated shaft. Hindtibia with 2 + 2 spurs. Female unknown.

Male genitalia

(Figs 5, 6). Uncus triangular, lateral weakly setose, wide at base, about four fifths as long as the basal width. Lateral margins slightly convex, apex bilobed with a small apical hollow. Gnathos arms fused ventrally, folded, their lateral margins serrate. Juxta long, triangular, tapers evenly or slightly concave, apex pointed, somewhat bent. Valva broad, simple, membranous, approximately the same width basally and apically. Apex round, setose. Valva setose from centre to apex. Costa slightly concave, sacculus nearly straight. Saccus wide, rounded, medially short, often bent trapezoid projection. Aedeagus narrow, slightly bent, apically 1.35-1.55 mm striated, no cornutus. Length of aedeagus: 3.05-3.2 (on average 3.0) mm.

Differential diagnosis.

The new species is very similar to its relatives Biston strataria (Hufnagel, 1767) (Fig. 4) and B. achyra Wehrli, 1936 (Fig. 3). Biston rosenbaueri sp. n. males can be separated from B. strataria by the distinct discal spot on hindwings, which is absent or hardly visible in B. strataria . B. achyra has on average less contrasting wing pattern, its tegulae and thorax are brownish grey and have no white blotches as can mostly be seen in B. rosenbaueri sp. n. and B. strataria . This species has also a distinct discal spot on hindwings. See Figs 1-4. In comparison with B. strataria , B. rosenbaueri sp. n. on forewing has postmedial line between the veins CuA2 and A2+A3 less excurved, oval, not somewhat conic tongue-like as it is in B. strataria ; but more prominent than in B. achyra . Antemedial line in B. rosenbaueri sp. n. also looks less extended along the A2+A3 than in B. strataria , but similar to that in B. achyra . For differences in male genitalia, see Table 1.

Distribution.

Biston rosenbaueri sp. n. is known from northern Croatia and northern Greece. The specimens have been collected at elevations between 200 and 1000 m.

Biology.

Unknown

Etymology.

The new species is named after the German lepidopterologist Frank Rosenbauer who collected male specimens of the new species in Greece.

Genetic data.

Contributed by Axel Hausmann, ZSM.

Biston strataria (Hufnagel, 1767): BIN: BOLD:AAB4693 (n=59 from Finland, United Kingdom, Netherlands, Germany, Austria, Switzerland, France, Spain, Italy, Greece including Crete, Morocco, Tunisia, north-eastern Turkey, Russia (Urals) and Turkmenya). Genetically homogenous, but North African populations slightly diverging (0.6%), one barcoded specimen from Turkmenya diverging by 1.0%. Nearest species: B. achyra from Israel (3.3%).

Biston rosenbaueri sp. n.:BIN: BOLD:ADA6153 (n=7 from Croatia: Island Krk, Gorski Kotar, Greece: Epirus). Genetically homogenous. Nearest species: B. achyra (4.1%).

Biston achyra Wehrli, 1936: BIN: BOLD:ABZ6431 (n=7 from Greece (Samos), Turkey, Israel, Lebanon). Genetically heterogenous, Israeli populations diverging from populations from Samos and southern Turkey by 2.2%. Nearest species: B. rosenbaueri sp. n. (4.1%).