Elachista dimicatella Rebel, 1903

Kaila, Lauri & Huemer, Peter, 2024, Elachista dimicatella sensu auctt. — a complex of neglected species diversity (Lepidoptera, Elachistidae) from European mountain systems, ZooKeys 1212, pp. 179-194 : 179-194

Elachista dimicatella Rebel, 1903

Elachista dimicatella Rebel, 1903: 100. Type locality: Ukraine, Marmaros.

Material examined.

Lectotype ♂, designated by Gaedike (1975: 244) ( NHMW). [pictures of adult and genitalia examined]

Poland • 1 ♂; Tatra Mts., Kościeliska Valley ; 1000 m a. s. l.; 49.30 ° N, 19.93 ° E; 22 Jun 1987; ex larva from Sesleria tatrae ; J. Buszko leg.; L. Kaila prep. 587; Elachista dimicatella Hering, L. Kaila det. 2004 ; 1 ♀, same collecting data but host plant Alopecurus pratensis ; MZH • 1 ♂; Tatra Mts., Wąwóz Kraków , DV 15, 1000 m a. s. l.; 49.23 ° N, 19.86 ° E; 2 Jun 2020; T. Baran leg.; gen. prep. J. Tabell 4390; DNA barcode voucher 16240 Lepid. Phyl.; MZH • 1 ♂; Tatra N. P., Mt. Bobrowiec ; 1300 m a. s. l.; 49.24 ° N, 19.78 ° E, spruce forest; 16 Jun 1996; K. Mikkola leg.; MZH • 2 ♂; Tatra N. P., Jesiolów Zl ; 1400 m a. s. l.; 27 Jul 1997; K. Mikkola leg.; MZH • 1 ♂; Tatra N. P., Chochołowska Valley, Bobroviec ; 1250–1350 m a. s. l.; 49.16 ° N, 19.83 ° E; 24 Jul 1997; K. Mikkola leg.; L. Kaila prep. 6345; MZH • 1 ♂; Tatra Mts., Giewont, Mnich Malolacki ; 1500 m a. s. l.; 49.25 ° N, 19.93 ° E; 24 Jul 1997; K. Nupponen & J. Junnilainen leg.; MZH • 3 ♀; Tatra Mts., Kominiarski Wierch ; 1700–1800 m a. s. l.; 49.24 ° N 19.83 ° E; 28 Jul 1997; K. Nupponen & J. Junnilainen leg.; L. Kaila prep. 6378; MZH • Tatra Mts.; 1400 m a. s. l.; 25. – 28 Jun. 1977; ex larva from Sesleria coerulea , Poa ; H. Steuer leg; ZSM .

Ukraine • 6 ♂ 2 ♀; Ivano-Frankivsk oblast, Verkhovyna district, Mt. Chivchen ; 1600–1760 m a. s. l.; 48.15 ° N, 24.82 ° E; J. Kullberg & T. Lievonen leg.; L. Kaila prep. 4653, 4827, 6383; DNA barcode vouchers 16160, 16161 Lepid. Phyl.; MZH • 6 ♂ 2 ♀; Ivano-Frankivsk oblast, Verkhovyna district, Burkut region ; 47.908 ° N, 24.698 ° E; 3. – 5 Jun 2003; J. Kullberg & T. Lievonen leg.; L. Kaila prep. 6379; DNA barcode voucher 16159 Lepid. Phyl.; MZH .

Diagnosis.

Elachista dimicatella is externally characterized by the creamy white head, the white base of the nearly black forewing reminiscent of E. diederichsiella Hering , straight and relatively narrow median fascia, and the usually medially confluent subcostal (tornal) and costal spots, often forming a steep angle towards apex. The antennae of the male are unicolourous grey in the male, in the female paler in apical half; in E. cottiella the antennae of both sexes are unicolourously dark grey, in E. niphadophanes the antennae of the male vary. In the male genitalia E. dimicatella is close to E. niphadophanes from which it differs by the somewhat longer phallus. From E. cottiella it is distinguished by the white pattern of forewings, that being somewhat silvery in E. cottiella . Subcostal and tornal spots are clearly separate in E. cottiella . In the male genitalia the most distinctive difference between E. dimicatella and E. cottiella is the markedly longer phallus in E. cottiella in which the shape of the juxta lobes is more rounded than in the other species. The antrum is significantly longer and narrower in E. cottiella than in E. dimicatella in which it is distinctly convex. Apophyses anteriores are thinner in E. dimicatella than in E. cottiella . More detailed diagnosis between E. dimicatella and E. cottiella are presented in the diagnosis of the latter species. The female of E. niphadophanes is unknown.

Redescription.

Habitus (Figs 2 , 3 ). Wingspan 8.5–11 mm, male on average larger than female. Labial palpus ascending, approximately as long as diameter of head, off-white to silvery grey above, fuscous below; 3 rd segment often paler than 2 nd segment. Head creamy white; neck tuft varying from white or grey to almost black, thorax dark grey, tegula in basal half dark grey, white in distal half. Antenna entirely dark grey in male, distally a little paler in female. Fore- and midleg dark grey; hindleg outwards dark grey, inwards off-white with also spurs, tibia and tarsal articles distally off-white. Ground colour of forewing very dark brown to nearly black; base white especially on dorsal side; white transverse fascia of varying width at 1 / 3 forewing length; similarly coloured subcostal and tornal spot at 3 / 4 forewing length, confluent forming medially outward directed fascia, in female sometimes separate; fringe as ground colour, at termen white. Underside of fore- and hindwing dark grey with concolourous fringe.

Male genitalia (Fig. 7 ). Uncus lobes widely apart from each other, separated by convex posterior margin of tegumen, ventrolaterally directed, tongue-shaped, 2 × as long as wide, distally round. Spinose knob of gnathos small as compared to average size within the E. bifasciella group. Valva slightly bent, broadest medially, 3.6 × as long as wide at its widest part medially; basal fold of costa extended to distal 3 / 4 of valva where it meets distal fold forming indistinct hump. Digitate process ¼ as long as valva, narrow and parallel-sided, with a few setae distally. Mesial margin of juxta lobes straight, meeting distal margin at a right angle, distal margin nearly straight, broadly setose. Vinculum tapered, distally v-shaped, no distinct median ridge. Phallus 0.75 × as long as valva, straight, distal end bifurcate; without cornuti; caecum short, round, posterior opening dorsally projected.

Female genitalia (Fig. 10 ). Papilla analis round in lateral view; membrane between papillae anales ventrally densely covered by minute spines, ventral margin otherwise with row of setae, setae longest at apex of papilla analis. Apophysis posterioris as long as papilla analis. Apophysis anterioris 2 / 3 × as long as apophysis posterioris. Ostium bursae in anterior margin of tergum 8, posterior margin convex; dorsal wall spinose; length of antrum slightly less than length of apophysis posterioris; antrum convex, colliculum posteriorly more and anteriorly less sclerotized, length as measured from anterior end of antrum to inception of ductus seminalis almost 3 × as long as apophysis posterioris; ductus bursae otherwise tubular, membranous, 1.5 × as long as antrum + colliculum, widened anteriorly, incepted in corpus bursae without clear limit; corpus bursae round, with small internal granules; signum elongate, dentate, broadest medially.

Molecular analysis.

BIN: BOLD: AAV 6449 (n = 3). Intraspecific average p - distance within BIN is 0.15 %, maximum distance is 0.15 %. The nearest neighbour is E. cottiella ( BIN: BOLD: AEM 6237) at a distance of 6.41 %.

Biology.

In the Polish Tatra Mountains the larvae were collected in late May and June, preferably feeding on Sesleria tatrae and Deschampsia caespitosa , and furthermore on Alopecurus pratensis , Calamagrostis arundinacea , C. villosa , Dactylis glomerata , Milium effusum , and Poa alpina . Adults were observed from late June to July. The habitat is described as grassland on sunny slopes, exclusively on calcareous soil at altitudes between 1000 and 1800 m ( Buszko and Baraniak 1989). Steuer (1976) gives a detailed description of the larva habits as leaf-miners in Sesleria coerulea .

Several additional host-plants published by Parenti and Varalda (1994) cannot be attributed to a host-species and require confirmation.

Distribution.

Carpathians: Poland (mainly Tatra mts.) ( Paluch et al. 2022), Slovakia ( Laštůvka et al. 2018), Ukraine (type-locality; Ivano-Frankivsk region) (Fig. 13 ). A unique record from eastern Austria ( Kasy 1980) requires confirmation. Occasional records from the Alps are considered as misidentifications, possibly representing the externally closely similar E. argentifasciella Höfner. Elachista dimicatella was originally described from Marmaros, which at that time was part of Hungary. However, after the collapse of the Austro-Hungarian monarchy, the type locality became part of what is now Ukrainian territory, a change that was mistakenly overlooked later (i. e., Gaedike 1975).

Figures

Figure 13. Proved records of Elachista cottiella sp. nov. (red dots), E. dimicatella (yellow dots) and E. niphadophanes (green dots).

Figures 2–6. Adults. 2 Elachista dimicatella, male, Poland 3 E. dimicatella, female, Poland 4 E. niphadophanes, male, France 5 E. cottiella sp. nov., male, paratype, Italy 6 E. cottiella sp. nov., female, paratype, Italy.

Figures 7–9. Male genitalia, with details enlarged 7 Elachista dimicatella, Ukraine, slide 4827 L. Kaila 8 E. niphadophanes, France, slide 7419 J. Nel 9 E. cottiella sp. nov., paratype, Italy, slide 6347 L. Kaila.

Figures 10, 11. Female genitalia 10 Elachista dimicatella, Ukraine, slide 6383 L. Kaila 11 E. cottiella sp. nov., paratype, Italy, slide 6381 L. Kaila.