Elachista drepanella, Kaila & Nupponen, 2018

Kaila, Lauri & Nupponen, Kari, 2018, A review of the Elachista subula Parenti species complex (Lepidoptera, Elachistidae), with descriptions of nine new Palearctic species, Zootaxa 4433 (3), pp. 401-433 : 408-410

Elachista drepanella sp. nov.

Figs. 6, 7, 8 , 28, 29, 30 , 53

Material examined. Type material: holotype ♂: Russia: Tuva, 52°04’N 94°22’E, 670 m, Ust-Ujuk, steppe hills 3.–5.vi.1995, J. Jalava & J. Kullberg leg. (L. Kaila prep. 1663; MZH) . Paratypes (25 ♂ 1 ♀): 3 ♂ with the same collection data as in the holotype (L. Kaila prep. 1668, 1678, 1680; MZH) ; Zabaikalie, Chita obl., Kyra , 900 m, 16. vii.1997, 1 ♂, A. Bidzilya, I. Kostyuk & O. Kostyuk leg. ( Coll. ZMKU) ; Altai Mts., 50°14–16’N 87°50–55’E, Kuraiskaja step, 1500–1700 m, 25. vi.2000, 7 ♂, T. & K. Nupponen leg. (L. Kaila prep. 3941, 3954, 3956, 3958, 4140, 4138, 4139; Coll. Nupponen, 1 ♂ in MZH) ; S. Buryatia, 50°58–59’N 106°38-40’E, 550–600 m, Chikoy Valley, 10 km S Novoselenginsk vill., sand dunes/sandy steppe, 23.–24. vi.2002, 2 ♂, K. Nupponen leg. (L. Kaila prep. 4154, 4155; Coll. Nupponen) . Kazakhstan: 44°24’39’’N 68°40’07’’E, 190 m, Muyunkum sands, 40 km N. Suzak settl., 4. v.2012, 2 ♂, K. Nupponen leg. (L. Kaila prep. 5918, DNA sample 25491 Lepid. Phyl., L. Kaila prep. 6069; Coll. Nupponen) ; 46°24’22’’N 59°35’30’’E, 180 m, 60 km E. Bozoi village, 7 km N. Aral Sea shore, 13. v.2010, 1 ♂, K. Nupponen leg. (L. Kaila prep. 5267, DNA sample 15348 Lepid. Phyl.; Coll. Nupponen) ; 43°48’45’’N 53°31’29’’E, 70 m, Sengirkum sands, Terekurpa well, 27. v.2011, 1 ♂, K. Nupponen leg. , (DNA sample 22514 Lepid. Phyl.; Coll. Nupponen); 47°37’43’’N 59°31’14”E, 190 m, N. Barsuki desert, 21 km S. Chelkar settl., 2.–3. vi.2011, 8 ♂ 1 ♀, K. Nupponen leg. (L. Kaila prep. 6106–6109; DNA samples 22174, 22175, 22178, 22179, 22180, 22511, 22505, 22518, 22562 Lepid. Phyl. ; Coll. Nupponen, MZH) .

Diagnosis. E. drepanella is a creamy white species, with no markings on forewing, and externally possibly indistinguishable from E. ameteria and E. scalpra . E. scalpra , however, is chalky white based on the few specimens known. The genitalia of E. drepanella genitalia are most similar to those of E. subula and E. cisoria , but E. drepanella is on average larger than these two species, both of which also have distinctive plical and discal spots on the forewing. The phallus is narrower in E. drepanella than in E. subula and E. cisoria , but the level of pressure applied in mounting of genital slide easily distorts this trait. The valva is large as related to other parts of the genitalia (difficult to express by measurements but easier to discern from photographs. Juxta lobes are generally similar to those of most other species. They are slightly longer than wide, and the median margin joins the distal margin at a sharp angle. The valva of E. drepanella is broader in general, and especially in distal half, than in both E. ameteria and E. scalpra . A disntinctive characteristic of E. drepanella is the presence of elongate, thickened scales on on costal side of valva around middle of valva’s length. The female genitalia are characterized by a swollen, rugose posterior part in the ductus bursae that is similar to that seen in E. subula and E. cisoria . It is 3x as long as wide in E. drepanella , 2x as long as wide in these other species.

Molecular characterization. The maximum intraspecific variation among the 12 included specimens was 0.46 %. Of the species included the closest taxon in terms of similarity of barcodes is E. cisoria (distance 2.18 %).

Description. Forewing length 5–7 mm. Labial palpus straight, white, length equal to diameter of head. Head, neck tuft, thorax, scape and pedicel of antenna creamy white; scape with distinctive pecten formed of elongate, creamy white scales; flagellum cream in basal third, distally brown. Fore- and midleg inwardly grey, outwardly white, tarsal articles distally shortly pale; hindleg pale grey, spurs darker grey, tibia and tarsus above grey with distally pale tibia and tarsal articles. Forewing unicolorous pale cream except basal third of costa narrowly nearly black. Fringe concolorous with forewing. Hindwing very pale grey, somewhat translucent with concolorous fringe. Underside of forewing dark grey, in basal third two pale longitudinal lines; fringe grey except white near apex. Underside of hindwing pale grey, translucent, except on costal side where it is darker grey; fringe pale grey.

Male genitalia. Uncus lobe nearly rounded, slightly broader than long; ventrally sparsely covered by setae especially along distolateral area, lobes separated by V-shaped incision, depth of which 1/3 the length of uncus. Spinose knob of gnathos drop-shaped or oval, about as long as the width of uncus lobe. Valva 4.4–4.5x as long as wide at its widest point in the middle and in cucullus, costa slightly concave in basal half, valva otherwise parallelsided; cucullus indistinctly delineated, rounded. Digitate process 0.2x as long as valva, parallel-sided, tongueshaped, distal 2/3 with setae. Juxta lobe as long as digitate process, its median margin straight, joining distal margin at a right angle, distal margin slightly convex; group of setae on somewhat rugose area near distal margin; lateral margin concave. Median plate of juxta developed as dorsally projected lobe. Vinculum short and broad, U-shaped. Phallus 0.6x as long as valva; approximately 9x as long as broad at its broadest place at distal 3/5; weakly bent, distally tapered to pointed apex. Vesica with cornutus that consists of oval, weakly sclerotized plate with one or two small blunt teeth.

Female genitalia. Papillae anales membranous with nearly rounded apex; dorsoventrally with Y-shaped connecting sclerotization. Apophysis posterioris slender, straight, 2x as long as papilla analis. Apophysis anterioris 2/ 3x as long as apophysis posterioris. Ostium bursae narrow, laterally sclerotized. Antrum tubular; anterior to inception of ductus seminalis ductus bursae inflated as wrinkled, oval-shaped dilation, length of which 1.5 times as long as antrum, width 1/3 its length. Narrow part of ductus bursae in posterior third with longitudinal foldings; ductus bursae otherwise gradually widened towards corpus bursae, anteriorly weakly granulose. Corpus bursae oval-shaped, posteriorly weakly granulose, no signum present.

Biology. E. drepanella inhabits different kinds of xerothermic steppe habitats and hot sandy deserts. The altitude of known localities ranges from 190 to 900 m. Immature stages are unknown.

Distribution. S. Kazakhstan, Russia (Transbaikalia, Buryatia, Tuva).

Etymology. The name is derived from the Greek word drepanon, a sickle. This refers to the shape of the distal part of the phallus.

Figures

FIGURES 6–8. Adults of E. drepanella Kaila, sp. nov. Scale 2 mm. 6. ♂ holotype. 7. ♂ paratype (Kazakhstan, Muyunkum sands). 8. ♀ paratype (Kazakhstan, Barsuki desert).

FIGURES 28–30. Male genitalia of E. drepanella Kaila, sp. nov.. Left: general image of genitalia, phallus in same scale. Right top: juxta and digitate process. Middle: cornutus as enlarged [not included in Fig. 29]. Right bottom: phallus as enlarged. 28. Holotype (L. Kaila prep. 1680). 29. Paratype (Russia: Altai: Kuray; L. Kaila prep. 3954). 30. Paratype (Kazakhstan: Muyunkum sands; L. Kaila prep. 5918).

FIGURES 53–54. Female genitalia of Elachista spp. 53. E. drepanella Kaila, sp. nov. Overview (Kazakhstan: Barsuki Desert; L. Kaila prep. 6109). 54. E. mus Parenti. Overview (Kazakhstan: Terektikum Sands, N. Aralsk Town).