Elachista oryx Sruoga & Kaila, 2019

Sruoga, Virginijus, Kaila, Lauri & Rocienė, Agnė, 2019, The Elachistinae (Lepidoptera: Gelechioidea, Elachistidae) of Thailand, with description of eight new species, European Journal of Taxonomy 574, pp. 1-34 : 8-10

Elachista oryx Sruoga & Kaila sp. nov.

urn:lsid:zoobank.org:act:71CD1D33-4385-478F-B455-AAB1353ADD58

Figs 14–23

Diagnosis

Elachista oryx Sruoga & Kaila sp. nov. is a small species with peculiarly coloured forewings ( Fig. 14 ) and a dorsoventrally flattened head, atypical of Elachista in general but typical of related species in the E. albrechti - heteroplaca species group (cf. Kaila 1998). In wing pattern and male genitalia, this species is most similar to Elachista heteroplaca Meyrick, 1934 (for illustrations, we refer to Kaila 1998: figs 1–5). The main differences in male genitalia between E. oryx Sruoga & Kaila sp. nov. and E. heteroplaca are: 1) digitate process in E. oryx Sruoga & Kaila sp. nov. is short and wide ( Figs 16 , 18 ), devoid of setae, in E. heteroplaca it is long and slender, with setae; 2) juxta lobe in E. oryx Sruoga & Kaila sp. nov. very long and narrow, in E. heteroplaca it is much shorter and wide; 3) vinculum in E. oryx Sruoga & Kaila sp. nov. is short, width/length ratio about 0.7 whereas in E. heteroplaca it is longer, width/length ratio about 0.4; 4) phallus in E. oryx Sruoga & Kaila sp. nov. is wide, long/ width ratio about 19, in E. heteroplaca it is slender, long/width ratio about 30; 5) in E. oryx Sruoga & Kaila sp. nov. the stout spine of valva is comparatively short, about 7.5 times as long as wide, in E. heteroplaca it is longer, about 12 times as long as wide; 6) vesica is with numerous tiny spines in E. oryx Sruoga & Kaila sp. nov., whereas in E. heteroplaca vesica is without such spines; 7) the boomerang-shaped sclerotization of tergum 8 in E. oryx Sruoga & Kaila sp. nov. ( Fig. 23 ) is noticeably wider than in E. heteroplaca .

Etymology

The species name is derived from the Latin ‘ oryx ’ (a kind of antelope or gazelle) in reference to the long, horn-like spines of valvae.

Type material

Holotype

THAILAND • ♂; Lampang, Muban Phichai ; 18°18ʹ15ʺ N, 99°31ʹ06ʺ E; 12 Jan. 2012; M.J. Pellinen leg.; MZH VS1 / 23.11.18.

Description

Male

EXTERNAL CHARACTERS ( Figs 14–15 ). Forewing length 2.6 mm; wingspan 5.8 mm (n = 1). Head: frons shiny whitish; vertex and neck tuft brownish grey, some scales with dark brown tips; labial palpus upwards curved, about 1.7 times as long as width of head, creamy white, third segment medially with few dark brown scales on outer side; scape creamy white, without pecten; flagellum greyish brown, basal articles weakly annulated with paler rings. Thorax dark grey brown. Forewing: ground colour light greyish brown, costa narrowly dark except at 1/5 where indistinctly delimited oblique white streak and at 2/5 where larger oblique white streak almost reaches fold; in the middle of wing at fold dark brown spot formed of slightly raised scales; tornal area whitish; narrow longitudinal blackish brown stripe to apex of wing; fringe scales greyish, fringe line blackish brown. Hindwing and its fringe scales greyish brown.

MALE GENITALIA ( Figs 16–23 ). Uncus lobes widely apart from each other, narrow, elongate, basally weakly dilated, distally distinctly broadened, ventral surface densely covered with long, hair-like scales. Tegumen short, anterior margin dorsomedially strongly and widely indented, almost meeting posterior margin. Basal arms of gnathos very long, basally strongly melanized, and strongly bent towards posterior direction, apically fused and covered with several tiny spines; spinose knob small, spinose area directed apically. Costa of valva weakly concave; from distal fold of costa long, strongly sclerotized spine, length of which almost ⅓ of that of valva. Cucullus divided into two lobes: wide triangular lobe where sacculus meets cucullus, and another slightly longer, narrow lobe in costal side. Digitate process short and wide, triangular, devoid of setae. Median plate of juxta with two pockets: anteriorly directed small, triangular pocket at ventral side, and posteriorly directed large and wide one at dorsal side. Juxta lobes long and narrow, tapering to apex, median margin straight and distinctly sclerotized, distal margin with few tiny setae and dorsally directed large group of long hair-like scales. Vinculum long, v-shaped, saccus short, blunt-tipped. Phallus about 1.4 length of valva, basally dilated, straight except apex slightly bent; caecum short, rounded with sclerotized ridge forming two small lobes; vesica with group of minute spines, distally joined with two sclerotized longitudinal plates; one long bent cornutus.

Female

Unknown.

Biology

Unknown. The specimen was collected by artificial light.

Flight period

The only known specimen was captured in mid-January.

Distribution

So far this species is known only from northern Thailand.

Figures

Figs 14–17. Elachista oryx Sruoga & Kaila sp. nov., holotype, ♂ (MZH VS1/23.11.18). 14. Adult. 15. Head, latero-frontal view. 16. General view of male genitalia (phallus removed). 17. Phallus. Scale bars: 14–15 = 1 mm; 16–17 = 0.1 mm.

Figs 18–23. Elachista oryx Sruoga & Kaila sp. nov., genitalia, holotype, ♂ (MZH VS1/23.11.18, in glycerol before permanent mounting in Euparal). 18. Lateral view. 19. Juxta, lateral view. 20. Proximal part of phallus. 21. Distal part of phallus. 22. Uncus lobes, dorsal view. 23. Distal part of abdomen, dorsal view. Scale bars = 0.1 mm.