Holotype. ♂, „ITALIA, Prov. Torino Alpi Cozie, 2150 m Colle delle Finestre 27.7.1990 leg. Huemer & Tarmann“ „YPO 58 ♂ P. Huemer“ (TLMF).

Paratypes. Italy: 13 ♂, 7 ♀, same data, genitalia slides YPO 59 ♂ P. Huemer, YPO 77 ♂ P. Huemer, DNA barcode IDs TLMF Lep 03106, TLMF Lep 03107, TLMF Lep 03108 (TLMF); 3 ♂, 6 ♀, same data, but V. delle Finestre, 1700 m, genitalia slides YPO 66 ♂ P. Huemer, YPO 67 ♀ P. Huemer (TLMF). France: 1 ♂, Dep. Hautes-Alpes, Nevache, 1950m, 31.7.2001, leg. Nel, genitalia slide 12937 J. Nel, DNA barcode ID TLMF Lep 03144 (TLMF); 1 ♂, Dep. Hautes-Alpes, Vallee de la Claree, 2000 m, 3.7.2002, leg. Nel, genitalia slide 14644 J. Nel, DNA barcode ID TLMF Lep 03142 (TLMF).

K. cottiensis resembles other taxa of the K. alternans-group in wing markings and colour (Figs 2–11), but the male differs in the on average smallest forewing length of 7.59 mm (n=14) vs. 8.75 mm (n=13) in K. wehrlii, 8.55 mm (n=26) in K. alternans, 8.05 mm (n=6) in K. alpmaritimae and 8.25 mm (n=6) in K. dimorpha. Compared to K. wehrlii and K. alpmaritimae, the whitish suffusion of the forewing is largely reduced. The ochre-brown markings, which are well present in K. alternans, are almost completely absent. The female of K. cottiensis is also distinctly smaller than K. alternans, with a forewing length of 6.13 mm (n=8) on average vs. 7.58 mm (n=11), whereas females of K. cottiensis and K. alpmaritimae are indistinguishable. K. wehrlii is insufficiently known from only a single worn female specimen. Compared to the genetically nearest neighbour K. dimorpha, which is similar in forewing length (6.0 mm, n=4), the hindwings are slightly less reduced and the ground colour of the forewing is much lighter. Diagnostic characters in genitalia are generally weak. The male genitalia differ from K. alpmaritimae by the medially strongly widened valva, from K. alternans by the more slender cornuti, from K. wehrlii by three instead of four cornuti, and from the nearest neighbour K. dimorpha by the distinctly longer phallus (1.65–1.70 mm vs. 1.32–1.36 mm) (Figs 12–21). The female genitalia show no diagnostic characters to related species of the K. alternans-group (Figs 22–31).

Male (Fig. 4). Head covered with erected whitish hair-like scales; antennae dark grey-brown, indistinctly lighter ringed; thorax and tegulae dark grey-brown. Forewing length 7.0–8.8 mm (Ø 7.59 mm; n=14); ground colour dark grey-brown, mottled with whitish scales, particularly in distal half, forming indistinct patches in fold and on costa at about 4/5; irregular black dots on veins and few brown scales in medial part of wing; oblique blackish fascia at about 1/3 to 1/2 indistinct; termen mixed whitish-grey, dark grey-brown in apical part; fringes light grey, darker in apical area. Hindwing dark grey, fringes with dark grey base, distal part light grey.

Female (Fig. 5). Head covered with erected whitish hair-like scales; antennae grey-brown, distinctly ringed whitish; thorax and tegulae whitish. Forewing length 5.8–6.3 mm (Ø 6.13 mm; n=8); ground colour whitish, mottled with black scales, particularly along veins and in tornal part, patches of brown scales in medial part of wing from base to end of cell; oblique blackish fascia at about 1/3 to 1/2 indistinct, separated into larger dash-like patch and reduced dot; termen whitish with some dark grey-brown mottling in apical part; fringes greyish-white, darker in apical area.

Male genitalia (Figs 14–15). Socii long and slender, with apical spine; anterior margin of tegumen with medial process; gnathos broadly tongue-shaped, smooth; valva moderately slender, length 0.66–0.70 mm, medially distinctly widened, maximum width of about 0.24–0.26 mm, densely covered with long hairs in medial part and short setae on ventromedial margin, ventromedial part weakly convex, distal part slender with ventrally convex and dorsally projected apex, costa strongly sclerotized with some distal dentation; sacculus oval, weakly confined, densely covered with strong setae; saccus sizeable in length, about 0.38–0.42 mm, stout, about same width throughout, apex rounded; phallus ca. 1.65–1.70 mm long and slender, straight, apically with distinct reticulate sculpture, uneverted vesica with ca. 0.76–0.80 mm long sclerotized part, three prominent needle-shaped, one single, the other basally connected, cornuti of about 0.46–0.51 mm in length.

Female genitalia (Figs 23, 28). Genitalia ca. 4.9 mm in length; papilla analis large, densely covered with long setae; apophysis posterior rod like, ca. 0.70 mm, about length of apophysis anterior; apophysis anterior rod like; posterior part bifurcated with straight dorsal and inwardly curved ventral branch; lamella postvaginalis with large sclerotized mediolateral patches, covered with microtrichia, medial area less sclerotized, posteriolateral part with hump, covered with some long setae; ostium bursae membranous; antrum weakly sclerotized, funnel-shaped; ductus bursae very long, about 2.8 mm, from entrance of ductus seminalis to transition into corpus bursae covered with finely granulous sculpture, particularly in posterior and anterior part, ductus bursae extended into posterior part of corpus bursae, entrance to corpus bursae weakly widened; corpus bursae well delimited, about 1.2 mm in length, ovoid, with small plate-like signum.

The average intraspecific divergence of the barcode region is 0.0% (n=5). The minimum distance to the nearest neighbour K. dimorpha is 1.86%, whereas the minimum divergence to K. alternans, K. alpmaritimae and K. wehrlii ranges from 2.65% and 2.98% to 3.63%, respectively.

The species name refers to the type locality in the Cottian Alps (Alpi Cozie, Alpes cottiennes).

(Fig. 32). Only known from a small area in the southwestern Alps (Cottian Alps) of Italy and France. An alleged K. alternans from the Graian Alps (Huemer and Tarmann 1992) likely refers to K. cottiensis, but the specimen in question could not be re-examined.

Host-plant and early stages unknown. The adults were collected in late July. The flight period can most likely be further prolonged, depending on snow coverage and elevation. A specimen collected earlier during the summer, on June 9^th, by Jäckh in Valle delle Finestre (Huemer and Tarmann 1992) probably belongs to K. cottiensis. The adults were collected during the day, flying freely in the morning hours and flushed out from their resting places with a bee-smoker. The species occurs in alpine grassland interspersed with calcareous rocks. Vertical distribution: from about 1700 m to 2150 m.

K. cottiensis described here was already suspected to be distinctive from K. alternans by Huemer and Tarmann (1992), who illustrated adults (Figs 6–7) and cornuti of male genitalia (Fig. 105).

Holotype. ♂, „Frankreich Dep. Hautes-Alpes Col Agnel, 2770 m 6°59'02"E, 44°41'10"N 4.8.2010, leg. Huemer TLMF 2011-010“ „BC TLMF Lep 01756“ „YPO 158 ♂ P. Huemer” (TLMF).

Paratypes. France: 7 ♂, 5 ♀, same data, genitalia slides YPO 149 ♂ P. Huemer, YPO 159 ♀ P. Huemer, DNA barcode IDs TLMF Lep 01757, TLMF Lep 01758, TLMF Lep 01759 (TLMF); 4 ♂, 1 ♀, same data, leg. Wieser (LMK).

K. dimorpha resembles other taxa of the K. alternans-group in wing markings and colour (Figs 2–11), but the male differs from the genetically nearest neighbour K. cottiensis by the on average distinctly larger forewing length of 8.25 mm (n=6) vs. 7.59 mm (n=14). Larger species are K. wehrlii with forewing length 8.75 mm (n=13) and K. alternans with 8.55 mm (n=26), whereas K. alpmaritimae with 8.05 mm (n=6) is of similar size. Furthermore, K. wehrlii and K. alpmaritimae have a much more prominent whitish suffusion on the forewing, whereas the ochre-brown markings of K. dimorpha rather resemble K. alternans. The female of K. dimorpha reflects a tendency to reinforced brachyptery and is distinctly smaller than K. alternans with a forewing length of only 6.0 mm (n=4) on average vs. 7.58 mm (n=11), whereas females of K. cottiensis and K. alpmaritimae are strongly suffused with whitish scales. K. wehrlii is insufficiently known from only a single worn female specimen. The male genitalia differ from all other taxa of the K. alternans-group by the distinctly shorter phallus with <1.40 mm vs. a minimum of 1.50 mm in other species (Figs 12–21). The female genitalia show no diagnostic characters to related species of the K. alternans-group (Figs 22–31).

Male (Fig. 6). Head covered with ochre-brown hair-like scales; antennae almost unicolorous dark grey-brown; thorax and tegulae mixed dark grey-brown and ochre-brown. Forewing length 8.0–8.4 mm (Ø 8.25 mm; n=6); ground colour dark grey, intensively mottled with light grey, ochre-brown and whitish scales, white medial patch in fold; black dots particularly on costal and subcostal veins; black patch near base and at end of cell, oblique blackish fascia at about 1/3 to 1/2 reduced to large patch in fold; termen mixed dark and light grey; fringes basally dark grey, distal part whitish-grey, darker in apical area. Hindwing dark grey, fringes with dark grey base, distal part whitish-grey.

Female (Fig. 7). Head covered with erected whitish hair-like scales; antennae grey-brown, indistinctly lighter ringed; thorax and tegulae whitish. Forewing length 6.0 mm (Ø 6.0 mm; n=4); ground colour whitish, mottled with dark grey and black, particularly along fold and in tornal part, few black dots along costal and subcostal vein, small patches of ochre-brown scales in medial part of wing particularly in fold and at end of cell; oblique blackish fascia at about 1/3 to 1/2 indistinct, separated into larger dash-like patch and reduced dot; termen mixed whitish and dark grey; fringes whitish-grey, with dark grey basal part near apex. Hindwing grey, fringes whitish-grey with darker basal part.

Male genitalia (Figs 16–17). Socii long and slender, with apical spine; anterior margin of tegumen with medial process; gnathos broadly tongue-shaped, smooth; valva moderately slender, length 0.71–0.72 mm, medially weakly widened, maximum width of about 0.26–0.28 mm, densely covered with long hairs in medial part and short setae on ventromedial margin, ventromedial part weakly convex, distal part moderately slender with ventrally convex and dorsally projected apex, costa strongly sclerotized with weak distal dentation; sacculus oval, weakly confined, densely covered with strong setae; saccus short, about 0.32 mm, stout, about same width throughout, apex rounded; phallus ca. 1.32–1.36 mm long and slender, straight, apically with distinct reticulate sculpture, uneverted vesica with ca. 0.58–0.60 mm long sclerotized part, three to four prominent needle-shaped cornuti of about 0.38–0.40 mm in length.

Female genitalia (Figs 24, 29). Genitalia ca. 4.9 mm in length; papilla analis large, densely covered with long setae; apophysis posterior rod like, ca. 0.72 mm, about length of apophysis anterior; apophysis anterior rod like; posterior part bifurcated with straight dorsal and inwardly curved ventral branch; lamella postvaginalis with large sclerotized mediolateral patches, covered with microtrichia, medial area less sclerotize, posterolateral part with hump, covered with some long setae; ostium bursae membranous; antrum weakly sclerotized, funnel-shaped; ductus bursae long, ca. 2.3 mm, posterior part from entrance of ductus seminalis anterior and anterior part covered with finely granulous sculpture, medial part with weak and hardly discernible sculpture, ductus bursae extended into posterior part of corpus bursae, entrance to corpus bursae weakly widened; corpus bursae well delimited, about 1.4 mm in length, ovoid, with small plate-like signum.

The average intraspecific divergence of the barcode region is low with 0.08%, ranging from a minimum of 0% to a maximum of 0.15% (n=4). The minimum distance to the nearest neighbour K. cottiensis is 1.86%, whereas the minimum divergence to K. alternans, K. alpmaritimae and K. wehrlii ranges from 3.15% and 3.64% to 4.3%, respectively.

The species name refers to the remarkable sexual dimorphism.

(Fig. 32). Only known from the type locality, the French side of Col Agnel (Cottian Alps), close to the Italian border.

Host-plant and early stages unknown. Based on the type locality, the host-plant is most likely Saxifraga cf. oppositifolia. The adults have been collected in early August during the early morning hours from about 7–10a.m. at low temperatures between 2–5 °C. Males were flying actively during this period in search for females. Both sexes were later found in copula, often sitting on cushions of their suspected host-plant. A single female was found at light, attracted from its nearby habitat and crawling upwards to the light tower, but unable to fly actively. From personal observations of PH, it is likely that the slightly reinforced brachyptery of K. dimorpha is combined with flightlessness. The species occurs in rocky habitat on siliceous soil. Vertical distribution: about 2800 m.

Fringes of the examined females seem partially lost and thus may lead to a biased impression of the extent of wing reduction.

Holotype. ♂, „FRANKREICH Dep. Alpes Maritimes Marguareis W-Hang Navela 2100–2200 m 21.–23.7.1990“„leg. Huemer, Tarmann“„YPO 79 ♂ P. Huemer“ (TLMF).

Paratypes. France: 9 ♂, 5 ♀, same data, genitalia slide YPO 55 ♂ P. Huemer (TLMF); 7 ♂, 2 ♀, same data, but 18.-19.7.1991, DNA barcode IDs TLMF Lep 01850, TLMF Lep 01851, TLMF Lep 03100, TLMF Lep 03101, TLMF Lep 03102, TLMF Lep 03103 (TLMF); 3 ♂, 5 ♀, same data, but 23.7.1990 (TLMF); 1 ♂, same data, but Punta Marguareis, 2450–2650 m, 23.7.1990 (TLMF).

K. alpmaritimae resembles other taxa of K. alternans-group in wing markings and colour (Figs 2–11), but the male with average forewing length of only 8.05 mm (n=6) is distinctly smaller than K. wehrlii with 8.75 mm (n=13) and K. alternans with 8.55 mm (n=26) and larger than K. cottiensis with only 7.59 mm (n=14). K. dimorpha with an average forewing length of 8.25 mm (n=6) is similar in size, but clearly differs by the largely reduced whitish suffusion of the forewing, a character stage which also applies to K. cottiensis and K. alternans, whereas K. wehrlii is intensely mottled whitish. The female with forewing length of only 6.06 mm (n=3) is distinctly smaller than that of K. alternans with 7.58 mm (n=11), but hardly separable from other species in size. Compared to the genetically nearest neighbour K. dimorpha, the hindwings are less reduced and the ground colour of the forewing is much lighter. The female of K. wehrlii is insufficiently described due to limited material, and the females of K. cottiensis and K. alpmaritimae are indistinguishable. The male genitalia differ from K. cottiensis by the medially weakly widened valva, from K. alternans by the more slender cornuti, from the nearest neighbour K. wehrlii by three instead of four cornuti, and from K. dimorpha by the distinctly longer phallus (1.52–1.58 mm vs. 1.32–1.36 mm) (Figs 12–21).

The female genitalia show no diagnostic characters to related species of the K. alternans-group (Figs 22–31).

Male (Fig. 10). Head covered with erected whitish hair-like scales; antennae dark grey-brown, indistinctly lighter ringed; thorax and tegulae dark grey-brown. Forewing length 7.0–8.5 mm (Ø 8.05 mm; n=6); ground colour blackish to dark grey-brown, intensely mottled with whitish scales, particularly from basal fifth to 4/5; veins with distinct black dots, particularly along costa, subcosta, cubital and anal veins, medial and radial veins with indistinct brown lines; oblique blackish fascia at about 1/3 to 1/2 indistinct; termen dark grey-brown; fringes light grey, with slightly darker base and indistinct fringe linge. Hindwing dark grey, fringes light greyish-white with slightly darker base.

Female (Fig. 11). Head covered with erected whitish hair-like scales; antennae grey-brown, indistinctly ringed whitish; thorax and tegulae whitish. Forewing length 5.9–6.3 mm (Ø 6.06 mm; n=3); ground colour whitish, mottled with few black scales, particularly along veins, patches of black scales near base and at distal end of cell; oblique blackish fascia at about 1/3 to 1/2 distinct, separated into two dashes; termen whitish with some blackish dots in apical part; fringes white. Hindwing grey, fringes whitish-grey.

Male genitalia (Figs 20–21). Socii long and slender, with apical spine; anterior margin of tegumen with medial process; gnathos broadly tongue-shaped, smooth; valva moderately slender, length 0.72–0.76 mm, medially weakly widened, maximum width of about 0.26–0.27 mm, densely covered with long hairs in medial part and short setae on ventromedial margin, ventromedial part weakly convex, distal part slender with ventrally convex and dorsally projected apex, costa strongly sclerotized with weak distal dentation; sacculus oval, weakly confined, densely covered with strong setae; saccus short, about 0.32–0.33 mm, stout, about same width throughout, apex rounded; phallus ca. 1.52–1.58 mm long and slender, straight, apically with distinct reticulate sculpture, uneverted vesica with ca. 0.62–0.66 mm long sclerotized part, three prominent needle-shaped, one single, the other basally connected, cornuti of about 0.42–0.44 mm in length.

Female genitalia (Figs 26, 31). Genitalia ca. 4.9 mm in length; papilla analis large, densely covered with long setae; apophysis posterior rod like, ca. 0.76 mm, about length of apophysis anterior; apophysis anterior rod like; posterior part bifurcated with straight dorsal and inwardly curved ventral branch; lamella postvaginalis with large sclerotized mediolateral patches, covered with microtrichia, medial area less sclerotized, posterolateral part with hump, covered with some long setae; ostium bursae membranous; antrum weakly sclerotized, funnel-shaped; ductus bursae very long, ca. 2.4 mm, from entrance of ductus seminalis to transition into corpus bursae covered with finely granulous sculpture, particularly in posterior and anterior part, ductus bursae extended into posterior part of corpus bursae, entrance to corpus bursae weakly widened; corpus bursae well delimited, about 1.2 mm in length, ovoid, with largely reduced plate-like signum.

The average intraspecific divergence of the barcode region is 0.0% (n=6). The minimum distance to the nearest neighbour K. wehrlii is 1.87%, whereas the minimum divergence to K. cottiensis, K. dimorpha and K. alternans ranges from 2.98% and 3.64% to 3.75%, respectively.

The species name is a made-up word which refers to the area of the type locality, the Alpes Maritimes.

(Fig. 32). Only known from the type locality, the Marguareis Massif, in the French Alpes Maritimes.

Host-plant and early stages unknown. The adults have been collected in the last third of July during the day, flying freely in the morning hours and flushed out from their resting places with a bee-smoker. The species occurs in rocky habitat on calcareous soil. Vertical distribution: from about 2100 m to 2650 m.

K. alpmaritimae described here was already suspected to be distinctive from K. alternans by Huemer and Tarmann (1992), who illustrated adults (Figs 8–9).

Holotype. ♂, „Italia Prov. Rieti Monte Terminillo 13°00,6'E, 42°29,0'N 1730–1780 m, 16.7.2010 leg. Huemer TLMF 2010-020“ „YPO 147 ♂ P. Huemer“ „TLMF Lep 01662“ (TLMF).

Paratypes. Italy: 1 ♂, same data, DNA barcode ID TLMF Lep 01661 (TLMF); 2 ♂, Prov. L´Aquila, NP Gran Sasso, ex Miniera di Lignite, 13°42,8'E, 42°25,6'N, 1750 m, 14.-15.7.2010, leg. Huemer, genitalia slide YPO 148 ♂ P. Huemer, DNA barcode IDs TLMF Lep 01663, TLMF Lep 01664 (TLMF).

K. apenninica is characterized by unusually slender forewings and a pure white colour with black pattern. Species from the K. apenninica-group are externally unmistakably distinguishable from one another both by wing pattern and colour (Figs 33–34, and Huemer and Tarmann 1992), but the genitalia of males are similar (Figs 35–38). However, in K. apenninica the saccus is distinctly shorter than in all other species with 0.23 vs. minimum 0.29 mm.

Male (Fig. 33). Head covered with whitish hair-like scales; antennae almost unicolorous dark grey with light grey apex; thorax and tegulae mixed dark grey and whitish. Forewing length 5.8–6.9 mm (Ø 6.4 mm; n=4); forewing slender; ground colour white, mottled with black; black dots on veins and in terminal area; black patch near base and oblique blackish fascia at about 1/3 to 1/2; fringes white with indistinct dark grey fringe line. Hindwing dark grey, fringes with dark grey base, distal part white.

Female. Unknown.

Male genitalia (Figs 35–36). Socii long and slender, with apical spine; anterior margin of tegumen with medial process; gnathos broadly tongue-shaped, smooth; valva slender, length 0.61 mm, max width 0.19 mm; densely covered with long hairs in medial part and short setae on ventromedial margin, ventromedial part weakly convex, distal part with ventrally convex and dorsally projected apex, costa strongly sclerotized with indistinct distal dentation; sacculus oval, weakly confined, densely covered with strong setae; saccus short, about 0.24 mm, slender, about same width throughout, apex rounded; phallus 0.95 mm long, slender, uneverted vesica with ca. 0.35 mm long sclerotized apical part, including 3 short cornuti of about 0.22 mm length [hardly discernible in situ].

Female genitalia. Unknown.

K. apenninica splits into two geographically separated haplogroups, which in our examination – based on limited material – did not reveal any morphological differences. The average intraspecific divergence of the barcode region is considerable with 1.05%, ranging from a minimum of 0% to a maximum of 1.69% (n=4). The minimum distance to the nearest neighbour K. pyrenaea is 5.47%.

The species name refers to the Apennines where all type specimens have been collected.

Only known from the Apennines in Central Italy.

Host-plant and early stages unknown, but the species probably feeds on an unidentified broad-leaved Saxifraga species growing on steep rocks. The adults have been collected in the last third of July from light. The species occurs in rocky habitat on calcareous soil. Vertical distribution: from about 2100 m to 2200 m.

Holotype. ♂, „ITALIA sept. Prov. Bergamo, Alpi Orobie Zambla Alta – Plassa 9°47'48"E, 45°54'12"N 1160 m, 24.6.2013 leg. Huemer“ „DNA Barcode TLMF Lep 09972“ „YPO 160 ♂ P. Huemer“ (TLMF).

Paratypes. Italy: 6 ♂, 6 ♀, same data, DNA barcode IDs TLMF Lep 09971, TLMF Lep 09973 (TLMF); 1 ♂, 1 ♀, same data, but e.l. 11.7.2013 (TLMF); 7 ♂, 2 ♀, same data, but leg. Mayr (coll. Mayr, Feldkirch); 1 ♂, Prov. Bergamo, Alpi Orobie, Val d´Arera, 2000 m, 14.–15.8.1992, leg. Huemer (TLMF); 1 ♀, Prov. Bergamo, Alpi Orobie, W. Ca. San Marco, 2100 m, e.l. 31.7.1992, leg. Huemer & Tarmann, DNA barcode ID TLMF Lep 03175 (TLMF).

K. orobiae largely resembles other taxa of the K. albescens-group in wing markings and colour, and cannot be unambiguously separated (Figs 39–48). Similarly, female genitalia exhibit no significant diagnostic characters for discrimination at species level (Figs 59–66, and Huemer and Tarmann 1992). The most reliable diagnostic characters in the species-group are found in the male genitalia (Figs 49–58). K. orobiae differs from K. klimeschi, K. albescens and K. helvetica by a much shorter saccus (0.32 mm vs. minimum 0.38–0.58 mm) which is only about half the length of the valva compared to the minimum 0.75 times the length of the valva in the other species. In K. inexpectata the saccus is slightly longer and furthermore without the apical widening of K. orobiae, K. albescens and K. helvetica. The two needle-shaped cornuti are similar in all species, with the exception of K. klimeschi with only one needle-shaped and one sub-ovate cornutus, and K. helvetica with cornuti of about 0.50 mm in length. The female genitalia largely resemble other species of the K. albescens-group with only quantitative differences, such as a longer ductus bursae than in K. albescens (1.6 mm vs. 1.3–1.4 mm), and the overall length of genitalia which exceeds K. klimeschi (4.2 mm vs. 3.5 mm).

Figures 49–54. 

Kessleria male genitalia. 49 K. klimeschi, holotype, Italy, Prov. Udine, Montasio, Malga Pecol, 1600 m, 24.6.1989 e.l., leg. Huemer & Tarmann, genitalia slide YPO 17 (TLMF) 50 idem, cornuti enlarged 51 K. helvetica, holotype, Switzerland, Wallis, Zermatt, 1850 m, 10.8.1980, leg. Whitebread, gen. slide 350 Whitebread (DNA barcode ID TLMF Lep 01868) (TLMF) 52 idem, distal part of phallus enlarged 53 K. inexpectata, paratype, France, Dep. Alpes Maritimes, Marguareis W-Hang, Navela, 2100–2200 m, 21.–23.7.1990, leg. Huemer & Tarmann, gen. slide YPO 63 (TLMF) 54 idem, distal part of phallus enlarged.

Figures 55–58. 

Kessleria male genitalia. 55 K. orobiae sp. n., holotype, Zambla Alta – Plassa, 1160 m, 24.6.2013 leg. Huemer, gen. slie YPO 160 (TLMF) 56 idem, distal part of phallus enlarged 57 K. albescens, ♂, Italy, Monte Baldo, Bocca di Navene, 14.7.1987, leg. Huemer & Tarmann, gen. slide YPO 19 (DNA barcode ID TLMF Lep 03131) (TLMF) 58 idem, distal part of phallus enlarged.

Figures 59–62. 

Kessleria female genitalia. 59 K. klimeschi, paratype, Italy, Prov. Udine, Montasio, Malga Pecol, 1600 m, 24.6.1989 e.l., leg. Huemer & Tarmann, gen. slide YPO 76 (TLMF) 60 K. inexpectata, paratype, France, Dep. Alpes Maritimes, Marguareis W-Hang, Navela, 2100–2200 m, 21.–23.7.1990, leg. Huemer & Tarmann, gen. slide YPO 74 (TLMF) 61 K. orobiae sp. n., paratype, Zambla Alta – Plassa, 1160 m, 24.6.2013, leg. Huemer, gen. slide YPO 161 (TLMF) 62 K. albescens, Italy, Monte Baldo, Bocca di Navene, 14.7.1987, leg. Huemer & Tarmann (TLMF).

Figures 63–66. 

Kessleria female genitalia, details of VIII abdominal segment enlarged. 63 K. klimeschi, paratype, Italy, Prov. Udine, Montasio, Malga Pecol, 1600 m, 24.6.1989 e.l., leg. Huemer & Tarmann, gen. slide YPO 76 (TLMF) 64 K. inexpectata, paratype, France, Dep. Alpes Maritimes, Marguareis W-Hang, Navela, 2100–2200 m, 21.-23.7.1990, leg. Huemer & Tarmann, gen. slide YPO 74 (TLMF) 65 K. orobiae sp. n., paratype, Zambla Alta – Plassa, 1160 m, 24.6.2013, leg. Huemer, gen. slide YPO 161 (TLMF) 66 K. albescens, Italy, Monte Baldo, Bocca di Navene, 14.7.1987, leg. Huemer & Tarmann (TLMF).

Male (Fig. 45). Head covered with white hair-like scales; antennae ringed dark grey and whitish; thorax and tegulae mixed dark grey and white, distally predominantly white, particularly tegulae. Forewing length 6.7–7.3 mm (Ø 7.03 mm; n=6); ground colour whitish-grey, intensively mottled with blackish-grey spots all over wing, few ochre-brown scales in dorsal part; blackish-grey patches at base of costa and at end of cell, oblique blackish-grey fascia at about 1/3 to 1/2 narrow and indistinct, medially separated; termen whitish-grey; fringes white, basally with distinct blackish-grey cilia line, apex with small dark grey tip. Hindwing dark grey, fringes with dark grey base, distal part white.

Female (Fig. 46). As male. Head covered with white hair-like scales; antennae ringed dark grey and whitish; thorax and tegulae mixed dark grey and white, distally predominantly white, particularly tegulae. Forewing length 5.9–6.6 mm (Ø 8.18 mm; n=5); ground colour whitish-grey, intensively mottled with blackish-grey spots all over wing, few ochre-brown scales in dorsal part; blackish-grey patches at base of costa and at end of cell, oblique blackish-grey fascia at about 1/3 to 1/2 narrow and indistinct, medially separated; termen whitish-grey; fringes white, basally with distinct blackish-grey cilia line, apex with small dark grey tip. Hindwing dark grey, fringes with dark grey base, distal part white.

Male genitalia (Figs 55–56). Socii long and slender, with apical spine; anterior margin of tegumen with medial process; gnathos broadly tongue-shaped, smooth; valva slender, length 0.60 mm, maximum width 0.18 mm; densely covered with long hairs in medial part and short setae on ventromedial margin, apical part ventrally convex, costa strongly sclerotized without dentation; sacculus oval, weakly confined, densely covered with strong setae; saccus moderate in length, about 0.32 mm, stout, distally widened with rounded apex; phallus 1.34 mm long, slender, uneverted vesica with ca. 0.70 mm long sclerotized apical part, including two prominent needle-shaped cornuti of about 0.40 mm length.

Female genitalia (Figs 61, 65). Genitalia ca. 4.2 mm in length; papilla analis large, densely covered with long setae; apophysis posterior rod like, ca. 0.70 mm, about length of apophysis anterior; apophysis anterior rod like; posterior part bifurcated with straight dorsal and inwardly curved ventral branch; ventral branch descending into patch like sclerite; lamella postvaginalis with sclerotized lateral patches, covered with microtrichia, medially membranous, posterolaterally with hump, covered with some long setae; ostium bursae membranous; antrum weakly developed, ring-like; ductus bursae long, about 1.6 mm, weakly curved in posterior part, from entrance of ductus seminalis to almost transition to corpus bursae densely covered with finely granulous sculpture; sculpture in posterior part nearly bacillary, distally increasingly granulous, entrance to corpus bursae widened, without sculpture; corpus bursae about 1.7 mm in length, saccate, posterior part folded, without signum.

The average intraspecific divergence of the barcode region is low with 0.31%, ranging from a minimum of 0.15% to a maximum of 0.46% (n=5). The minimum distance to the nearest neighbour K. albescens is 2.66%, whereas the minimum divergence to K. inexpectata, K. helvetica and K. klimeschi ranges from 3.14% and 3.46% to 9.53%, respectively.

The species name refers to the Orobian Alps (Alpi Orobie) in northern Italy, where the type locality is situated.

(Fig. 67). Only known from Zambla Alta – Plassa and few nearby localities in the Orobian Alps (Prov. Bergamo, Italy).

Figure 67. 

Distribution pattern of the Kessleria albescens-group from examined material.

The larval habits are insufficiently known, but based on our observations, the larva lives in the shoots and as a leaf-miner in basal leaves of Saxifraga paniculata and Saxifraga sp. Mined leaves are partially spun together and covered with a fine silken web. The adults have been collected from the Saxifraga-cushions or nearby rock during the day. In the first few hours of the night they have been observed with a head-lamp flying actively around the larval habitat or sitting near the host-plant. The adult is on the wing from late June to mid-August, depending on altitude and snow coverage. Bred specimens date from mid to late July. K. orobiae occurs in rocky habitat both on calcareous and silicous soil. Vertical distribution: from about 1100 m to 2100 m.