Elachista minor, Sruoga, 2022

Sruoga, Virginijus, 2022, New species and records of Elachistinae (Lepidoptera: Gelechioidea, Elachistidae) from Nepal, Zootaxa 5100 (4), pp. 573-584 : 578-579

Elachista minor sp. nov.

( Figs 17–23 )

Type material. Holotype: ♂, Nepal, 70 km W Kathmandu, Baikunthapuri , 19.iv.1995, V. Sruoga leg. Gen. prep. VS505 (VU).

Diagnosis. Elachista minor belongs to the E. praelineata species group (defined by Kaila 1999b). It is a small, dark-coloured species with distinct wing markings. In wing pattern and male genitalia, this species is similar to E. nepalensis Traugott-Olsen, 1999 , known from northern-central Nepal ( Traugott-Olsen 1999) and E. kurokoi Parenti, 1983 , known from Japan, Korea ( Parenti 1983; Sugisima 2005a; Koo et al. 2021), and from the same locality as E. minor . The main differences in male genitalia between E. minor , E. nepalensis and E. kurokoi are: 1) the uncus lobe is short in E. minor , whereas it is much longer in E. nepalensis and E. kurokoi ; 2) the vesica without spines in E. minor , whereas it has a group of small spines in E. nepalensis and E. kurokoi ; 3) the saccus is wide apically in E. minor , whereas it is pointed in E. nepalensis and E. kurokoi .

Male ( Figs 17, 18 ). Forewing length 2.5 mm; wingspan 5.5 mm (n=1). Head: frons shiny, creamy white; vertex and neck tuft brownish grey, powdered with dark brown-tipped scales; labial palpus upwards curved, diverging, about 1.3 times as long as width of head, creamy white, third segment greyish brown; scape greyish brown, without pecten; flagellum greyish brown, weakly annulated with paler rings. Thorax, tegula and ground colour of forewing blackish brown, weakly mottled by darker tipped scales. Forewing with transverse fascia antemedian, blurred, white, medially interrupted, indistinct white spot at 2/3 of costa, another similar spot before it on dorsal margin; fringe scales grey brown, fringe line brownish black. Hindwing blackish brown; fringe slightly paler.

Female. Unknown.

Male genitalia ( Figs 19–23 ). Uncus lobes small, widely separated from each other, ventrally directed, triangular shaped, slightly longer than their width, setae on ventral surface long. Spinose knob of gnathos rounded, tapered towards apex. Valva long and narrow, about five times as long as wide; basal fold of costa extended to 1/2 of valva, beyond it with broad hump; cucullus very long, slightly bent towards costa. Median plate of juxta with a pair of small dorsally directed lateral pockets. Juxta lobes rounded, slightly truncate, ventral surface distally with long setae, median margin straight, joining rounded distal margin at an obtuse angle, distal margin convex. Digitate process reduced to small, bluntly triangular lobe, without setae. Vinculum V-shaped, with a strong median ridge, tapered into short blunt-tipped saccus. Phallus about 0.6 as long as valva, bent at 2/5 from caecum, broad basally, gradually tapered towards pointed apex; vesica without cornuti.

Biology. Unknown.

Flight period. Based on the specimen available, adults fly in April.

Distribution. So far this species is known only from central Nepal.

Etymology. The species name is derived from the Latin minor (smaller in size) in reference to the small size of uncus lobe.

Figures

FIGURES 17–20. Elachista minor sp. nov., holotype. 17, adult male. Scale bar 1 mm; 18, head, latero-frontal view; 19, general view of male genitalia (phallus removed); 20, phallus. Gen. prep. VS505. Scale bar 0.1 mm.

FIGURES 21–23. Elachista minor sp. nov., holotype. 21, central part of male genitalia; 22, tegumen and uncus lobe, lateral view, in glycerol before permanent mounting in Euparal; 23, distal part of abdomen, dorsal view. Gen. prep. VS505.