Elachista obtusella, Sruoga, Virginijus, 2008

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

Elachista obtusella sp. nov.

Figs. 3 , 9, 10

Type material. Holotype: ɗ, Nepal 15 km SW Kathmandu Hattiban, pine forest 1500 m., 2.iii.1995, K. Mikkola & A. Wikberg leg.; genitalia slide no. 1513 ( MZH).

Condition of the type material. The single specimen is in rather fair condition, the wings are spread; the frons is slightly abraded; the right antenna and right labial palpus are broken.

Diagnosis. In male genitalia E. obtusella resembles E. stichospora Meyrick , known from India ( Meyrick 1932; Sruoga & Diskus 2006). The main differences in male genitalia between E. obtusella and E. stichospora are:

(1) the sacculus of E. obtusella is almost straight; in E. stichospora it is medially convex;

(2) the saccus of E. obtusella is shorter and wider;

(3) the phallus of E. obtusella is nearly as long as valva, curved at base and apical 1/3, apex without triangular tooth; in E. stichospora phallus conspicuously longer than valva, curved at basal and apical 1/6, apex with small triangular tooth;

(4) the vesica of E. obtusella is without cornutus; vesica with an arrow-shaped cornutus in E. stichospora .

Description. Male ( Fig. 3 ). Forewing length 3.4 mm, wingspan 7.2 mm. Head: Vertex and neck tuft mottled due to grey-brown tips of whitish scales; frons whitish with some metallic lustre; labial palpus whitish above, fuscous below; flagellum brownish, indistinctly ringed. Thorax: Forewing pale, greyish brown, mottled by brownish grey tipped scales. Dark brown 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 white, fringe line dark brown. Hindwing dark brown, its fringe scales somewhat paler.

Male genitalia ( Figs. 9, 10 ). Uncus lobes curved, basally bulbous, narrowed towards tip; ventral surface covered with mixture of short-thick, and long-slender setae. Basal arms of gnathos reinforced, spinose knob large and oval. Valva about 5 times longer than wide; sacculus basally straight or slightly expanded, distally with stout spine; cucullus neither expanded nor produced towards costa; basal fold of costa extended to 2/3 of valva, where it meets distal fold forming a distinct hump. Digitate process basally widened. Medial margin of juxta lobes strongly sclerotized; lobes rounded, with few short setae. Vinculum large, produced into long parallel-sided and blunt tipped saccus. Phallus long and slender, almost as long as valva, gently arcuate in apical 1/3; apex tapered; vesica without cornuti or spines.

Female. Unknown.

Biology. The single known specimen was collected 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 obtusella is only the second species of this group recorded from Nepal.

Etymology. The species name is derived from the Latin obtusus (blunt, dull) in reference to the peculiarly blunt apex of the saccus.

Figures

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

FIGURES 9 – 10. Elachista obtusella, male genitalia, holotype. 9, general view (phallus removed); 10, phallus. Genitalia slide No. 1513 (MZH). Scale bar 0.1 mm.