Kessleria orobiae, Huemer, Peter & Mutanen, Marko, 2015

Huemer, Peter & Mutanen, Marko, 2015, Alpha taxonomy of the genus Kessleria Nowicki, 1864, revisited in light of DNA-barcoding (Lepidoptera, Yponomeutidae), ZooKeys 503, pp. 89-133 : 107-112

Taxon classification Animalia Lepidoptera Yponomeutidae

Kessleria orobiae sp. n.

Type material.

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).

Diagnosis.

Kessleria orobiae largely resembles other taxa of the Kessleria 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). Kessleria orobiae differs from Kessleria klimeschi , Kessleria albescens and Kessleria 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 Kessleria inexpectata the saccus is slightly longer and furthermore without the apical widening of Kessleria orobiae , Kessleria albescens and Kessleria helvetica . The two needle-shaped cornuti are similar in all species, with the exception of Kessleria klimeschi with only one needle-shaped and one sub-ovate cornutus, and Kessleria helvetica with cornuti of about 0.50 mm in length. The female genitalia largely resemble other species of the Kessleria albescens -group with only quantitative differences, such as a longer ductus bursae than in Kessleria albescens (1.6 mm vs. 1.3-1.4 mm), and the overall length of genitalia which exceeds Kessleria klimeschi (4.2 mm vs. 3.5 mm).

Description.

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 bi furcated 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.

Molecular data.

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 Kessleria albescens is 2.66%, whereas the minimum divergence to Kessleria inexpectata , Kessleria helvetica and Kessleria klimeschi ranges from 3.14% and 3.46% to 9.53%, respectively.

Etymology.

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

Distribution

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

Ecology.

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. Kessleria orobiae occurs in rocky habitat both on calcareous and silicous soil. Vertical distribution: from about 1100 m to 2100 m.