Elachista tuberella, Sruoga, Virginijus, 2008

Sruoga, Virginijus, 2008, Three new species of Elachista Treitschke (Lepidoptera: Elachistidae: Elachistinae) from Nepal, Zootaxa 1821, pp. 59-66 : 62-64

Elachista tuberella sp. nov.

Figs. 2 , 7, 8

Type material. Holotype: ɗ, Nepal: 6800’ [~ 2070 m], Kathmandu Dist., Kakani, 1–2.vi.1983; mixed secondary scrub; Allen, Brendell, Robinson, Tuck, Brit. Mus. 1983–222; genitalia slide no. 29588 ( BMNH).

Paratypes: 1 ɗ, data as holotype; genitalia slide no. 29590 ( BMNH); 1 ɗ, Nepal 15 km SW Kathmandu Hattiban, pine forest 1500 m., 2.iii.1995, K. Mikkola & A. Wikberg leg.; genitalia slide no. 1512 ( MZH); 1 ɗ, same data; genitalia slide no. 2074 ( MZH).

Condition of the type material. Relatively well-preserved. Holotype with incompletely spread wings, the terminal fringe scales of the forewing are slightly abraded, and the left antenna is broken near the middle. Although the forewings are somewhat rubbed in the paratypes, the pattern is clear.

Diagnosis. In wing pattern the species is hardly distinguishable from many others. In male genitalia E. tuberella very closely resembles E. deficiens Meyrick , known from Sri Lanka ( Meyrick 1922; Sruoga & Diskus 2006). The main differences between E. tuberella and E. deficiens are:

(1) the phallus of E. tuberella has a hump at 1/2 and is curved at apical 1/4; in E. deficiens the hump is at apical 1/3 and phallus is curved at apical 1/3;

(2) the incision between the juxta lobes of E. tuberella is Y-shaped; in E. deficiens it is V-shaped.

Description. Male ( Fig. 2 ). Forewing length 3.2–3.8 mm, wingspan 6.9–8.2 mm. Head: Vertex and neck tuft mottled due to grey-brown tips of whitish scales; frons whitish with some metallic lustre; labial palpus white with some shine above, brownish below; antenna grey-brown, indistinctly ringed. Thorax: Tegulae and forewings greyish brown, mottled by brownish grey tipped scales. Blackish brown tipped scales beyond the middle of wing forming two irregular spots near the costal and tornal margins. Same scales present in apical part, where they form an elongate spot. Fringe scales grey except at apex whitish, fringe line blackish brown. Hindwing grey-brown, its fringe scales somewhat paler.

Male genitalia ( Figs. 7, 8 ). Uncus lobes outwardly produced and curved, narrowed towards tips; ventral surface covered with mixture of short and thick, and long and slender setae. Basal arms of gnathos reinforced, spinose knob large, subquadrate. Valva broadest in basal part; sacculus weakly concave medially, distally with prominent, stout spine; cucullus rounded; basal fold of costa extended to 2/3 of valva, where it meets distal fold forming a small hump. Medial margin of juxta lobes strongly sclerotized, with few setae distally, incision between lobes wide. Digitate process weakly expanded just before middle, distally slightly dilated, inner surface with short and thin setae. Vinculum with long and narrow saccus. Phallus slightly shorter than valva; medially with triangularly shaped hump, strongly curved at apical 1/4.

Female. Unknown.

Biology. Adults were collected in mixed secondary scrub in early June and in a pine forest in early March. Larval biology is unknown.

Distribution. Nepal, Kathmandu District.

Remarks. This species belongs to the E. freyerella species group sensu Kaila (1999b). Elachista tuberella is the first species of this group recorded from Nepal.

Etymology. The species name is derived from the Latin tuber (protuberance, excrescence) in reference to the peculiar hump in the middle of the phallus.

Figures

FIGURES 1 – 3. Wings of Elachista species. 1, E. ievae; 2, E. tuberella; 3, E. obtusella. Scale bar 1 mm.

FIGURES 7 – 8. Elachista tuberella, male genitalia, holotype. 7, general view (phallus removed); 8, phallus. Genitalia slide No. 29588 (BMNH). Scale bar 0.1 mm.