Elachista dimorphella Kaila & Tokar 2026, sp. nov.

Elachista dimorphella Kaila & Tokár sp. nov. Figs 1–6, 13, 14, 21, 24 Material examined. Holotype. ♀, • Croatia, Zaostrog-Kosovići, Rilić Mts, 300 m (43.0922°N, 17.1726°E), 26. vi. 2006, DNA sample 22169 Lepid. Phyl., leg. Z. Tokár, in Coll. Tokár. Paratypes. • Croatia, Istria, Pula, 30 m (45.5041°N, 13.5017°E), 14. – 19. v. 1990, 5 ♂, Z. Tokár prep. 321, L. Kaila prep. 4420, DNA sample 16946 Lepid. Phyl. [unsuccessful], leg. Z. Tokár, in Coll. Tokár, J. Liška & MZH; • Zaostrog, 180 m (43.0860°N, 17.1750°E), 8. vii. 2004, 1 ♂, Z. Tokár prep. 14955, 1 ♀, leg. Z Tokár, in Coll. Tokár; the same locality, 9. vii. 2004, 4 ♂, Z. Tokár prep. 8833, 14675, L. Kaila prep. 4421, DNA sample 16947 Lepid. Phyl., 7 ♀, Z. Tokár prep. 8711, 8883, 10842, 14972, 14972, 14973, 14974, DNA sample 19978 Lepid. Phyl., leg. Z. Tokár, in Coll. Tokár & MZH; the same locality, 8. – 9. vii. 2004, 1 ♀, L. Kaila prep. 4422, DNA sample 21353 Lepid. Phyl., leg. Ľ. Srnka, in Coll. Ľ. Srnka; • Zaostrog - Kosovići, Rilić Mts, 300 m (43.0922°N, 17.1726°E), 26. vi. 2006, 12 ♂, Z. Tokár prep. 14969, 1470, 14971, 2 ♀, Z. Tokár prep. 10843, 14673, leg. Z. Tokár, in Coll. Tokár; • Bilišane, 300 m (44.1029°N, 15.4608°E), 30. vi. 2006, 1 ♂, DNA sample 22167, leg. Z. Tokár, in Coll. Tokár; • Istria, Rovinj, Kokuletovica, 50 m (45.0546°N, 13.7198°E), 3. v. 2016, 1 ♂, TLMF_Lep_24106, leg. H. Deutsch, in Coll. TLMF; • Zadar County, Zaton Obrovački, 16. vi. 2019, 152 m (44.25°N, 15.681°E), 1 ♀, KBE_2019301, leg. K. Berggren, in Coll. Berggren. Italy: • Prov. Veneto, VE Caorle, küste [coast], 1–4 m, (45.59°N, 12.87°E), 7. vi. 2012, 1 ♀, DNA sample 25469 Lepid. Phyl., leg. T. Meyr, in Coll. MZH. Slovenia: • Petrinjski kras near Petrinje, 450 m (45.3357°N, 13.5424°E), 3. vi. 2005, 1 ♂, Z. Tokár prep. 8997, DNA sample 22609 Lepid. Phyl., 1 ♀, Z. Tokár prep. 8994, L. Kaila prep. 5474, DNA sample 21400 Lepid. Phyl., leg. Z. Tokár, in Coll. Tokár; • Primorska, Brestovica, 5. vi. 2013, 60 m (45.8122°N, 13.6191°E), 1 ♀, TLMF_Lep_24096, leg. H. Deutsch, in Coll. TLMF. Description. Female adult (Figs 1–3). Wingspan 7.5–8.5 mm. Labial palpus upcurved, third segment approximately the same length as second segment, yellowish white. Head, neck tuft, tegula, and scape of antenna yellowish white. Flagellum thick, white, ringed brown. Legs yellowish grey. Forewing ground colour yellowish white, variably with yellow to honey-yellow pattern and sparsely scattered, light brown scales, especially along the apex of the fringe on the termen. Fringe scales concolorous with forewing ground colour. Hindwing yellowish grey, fringe slightly lighter. Underside of forewing more densely dusted with brown. Male adult (Figs 4–6). Wingspan 6.5–7.7 mm. Labial palpus upcurved, as long as diameter of head, off-white, somewhat fuscous below. Head, neck tuft, tegula, thorax, scape and pedicel of antenna unicolorous grey or intermixed with paler scales. Flagellum thick, unicolorous grey. Legs ochreous grey. Forewing ground colour grey, variably with faint, irregular pattern formed of darker grey scales. Fringe scales concolorous with forewing ground colour. Hindwing dark grey with concolorous fringe. Underside of wings dark grey, with concolorous fringe. Female genitalia (Figs 21, 24). Papilla analis membranous, somewhat tapered towards nearly round apex; ventrally connected with inverted Y-shaped sclerotisation. Apophysis posterioris straight, as long as the basally curved apophysis anterioris. Ostium bursae round, dorsal wall without sclerotisation or spines. Antrum and colliculum indistinguishable, together 2 / 3 as long as apophysis posterioris. Remaining part of ductus bursae approximately 3 × as long as apophyses, membranous, without internal spines. Ductus bursae not distinctly separable from corpus bursae. Corpus bursae oval, with two rows of small internal spines. Male genitalia (Figs 13, 14). Uncus lobe nearly twice as long as broad at its broadest point, evenly tapered towards pointed apex, with few short setae distolaterally, incision separating uncus lobes 1 / 4 of length of uncus. Spinose knob of gnathos oval, twice as long as broad. Valva 3 × as long as broad at its broadest point in the middle; costa basally straight, distinctly convex in distal third; sacculus broad basally, straight beyond middle; cucullus weakly bent towards costa. Digitate process small, about 1 / 7 × as long as of valva, distally dilated, blunt and setose, ventral margin weakly convex. Juxta lobes basally widely separated from each other, round; their median margin convex, lateral margin concave; distal margin with a few short setae; median plate with shallow dorsally directed median sac. Vinculum with minute saccus. Phallus 0.6–0.75 × as long as valva, straight, 4.5 × as long as broad at its broadest point at distal 2 / 3. No cornuti present. Female diagnosis. The female’s forewing is yellowish-white with yellow to honey-yellow pattern, and to a varying extent sparsely scattered with brown scales, especially along the apex of the fringe on the termen. It is externally not easy to associate with the closest relatives of the E. bedellella group, but can rather be mixed with almost any Elachista species with a yellowish-white to yellow forewing colour. Among species of the E. bedellella group it is externally similar to species such as E. slivenica Kaila, 2007, E. ohridella Parenti, 2001, and E. mariae Kosorín & Tokár, 2024. The genitalia, however, have characters that differentiate all these species. In the E. argentella group, a complete revision of the complex of variably yellow species in the E. cingillella subgroup is not available (Kaila and Junnilainen 2002), where at least E. subalbidella Schläger, 1847 and E. laetella Rebel, 1930 of the named species are externally similar to the unicolorous yellowish-white specimens of E. dimorphella. The female genitalia of E. dimorphella are characterised by a paired band of small spines in the corpus bursae, while the yellow representatives of the E. cingillella species group have a pair of small signa. Similar spine bands as in E. dimorphella are also present in E. constitella (Figs 22, 25), and E. maculata (Figs 23, 26). In E. constitella there are three or four, indistinctly fused rows. In E. maculata there are two elongate areas of coarse spines. These species are also differentiated by the narrower ostium bursae in E. dimorphella (Fig. 21) and its unmarked ductus bursae, which is granulose in E. constitella (Fig. 22) and E. maculata (Fig. 23). The ductus bursae and the corpus bursae are fused without a distinct division, but clearly identifiable in E. constitella and E. maculata. In the subgenus Elachista there are several externally more or less similar species, and their separation from species of subgenus Aphelosetia on the female genitalia is easiest to recognise by the presence of a Y-shaped sclerotisation on the ventral side between the papillae anales in species of Aphelosetia, unlike in the subgenera Atachia and Elachista. Male diagnosis. The male is externally similar to several other darker species, or putative species, that are related to E. atrisquamosa Staudinger, 1880. The identity of E. atrisquamosa, described from “ Kleinasien, Karasdere ” [Türkiye, Amasya, Kara Dere], itself is still uncertain due to the absence of recent material that could with certainty be associated with this species, and due to the existence of several similar species or taxa with quite divergent barcode BINs resembling the illustrations of the holotype of E. atrisquamosa (see Nielsen and Traugott-Olsen 1978) from the Balkan Peninsula and Western Türkiye. The most striking characteristics of the male E. dimorphella from all other related taxa are the broad forewing shape, and the thick and unicolorous grey flagellum of the antennae. The wing pattern of the male is rather weak and irregular. The male genitalia are distinguished from most described, related, species by the relatively long tapered uncus lobes. Perhaps the most similar male genitalia are in E. vegliae Parenti, 1978 (Fig. 20), which also possess a broad phallus. Its juxta lobes are, however, medially more produced, and the apex of the phallus is somewhat bent, unlike in E. dimorphella (Figs 13, 14). Externally, males of these species can be differentiated by the flagellum of the antenna which is unicolorous grey and thick in E. dimorphella, narrower and clearly annulated with pale rings in E. vegliae. E. vegliae is also generally paler (Parenti 1978). The female of E. vegliae is unknown. Similar but even more pronounced elongate and tapered uncus lobes are found in E. ohridella, E. mariae, E. laurikailai Varenne & Nel, 2020 (Fig. 18), and E. nolckeni Šulcs, 1992 (see also Baran 2002; Kosorín and Tokár 2024; Kaila et al. 2025). The forewing ground colour of all these species is more or less yellowish also in the male (though in E. laurikailai it has some pale grey suffusion), their wing shape is narrower, and the flagellum of the antenna is narrower in these species as compared with E. dimorphella. It should be mentioned that the specimen that Traugott-Olsen (1990) stated to be the previously unknown male of E. constitella is misidentified and represents E. maculata. We give below illustrations of the holotype of E. maculata, and a diagnosis of the male of the probably true E. constitella. Distribution. Elachista dimorphella sp. nov. is currently known from a small number of localities near the Adriatic Sea: Italy – Region of Veneto, Caorle, Slovenia – Petrinjski kras, Brestovica, Croatia – Istria, Pula, Rovinj; Dalmatia, Bilišane, Zadar County; Zaton Obrovački, Zaostrog. The distribution has been recorded from near sea level to approximately 450 m (Petrinjski kras). The locality near Zaostrog is shown in Fig. 27. Biology. The immature stages and the host plants are unknown. Adults were collected from early May to early July, mostly in light-traps. Some of them were disturbed from the low undergrowth before suns