Elachista scoteina, Kaila, 2017

Kaila, Lauri, 2017, First records of Elachistinae from New Caledonia: evidence of repeated dispersal events with Australia (Lepidoptera, Gelechioidea, Elachistidae), Zootaxa 4300 (4), pp. 536-550 : 540-541

Elachista scoteina sp. nov.

Figs 3 , 12

Type material. Holotype ♂: New Caledonia 22°3’S 166°26’40’’E Mt. Dzumac , 820 m, 25.Oct.1986 UV trap R.

Brown & O. Pellmyr leg. (USNM), genitalia slide by L. Kaila USNM 142.816. Paratypes: 3 ♂; 2 ♂ with the same collection data as in the holotype, 1 ♂ collected 2.Nov.1986; genitalia slides by L. Kaila USNM 142,817, 142,813, (USNM, 1 paratype with genitalia slide L. Kaila 6103 in MZH).

Diagnosis. Elachista scoteina is a medium-sized elachistine species with forewing ground colour mottled, leaden grey. The only wing pattern is formed by small plical and discal spots. The male genitalia are most similar to those of E. physalodes Kaila, 2011 that occurs in Australia and New Zealand. These species, as well as the closely related E. gerasmia Meyrick, 1889 , are characterized particularly by their prolonged juxta lobes. E. gerasmia is readily distinguished by its larger size and forewing colour that varies from ochreous to dark chocolate brown. E. physalodes is more narrow-winged than E. scoteina and its forewing is not as mottled. The male genitalia of E. scoteina and E. physalodes differ as follows: the spinose knob of gnathos is rounded in E. physalodes , elongate with straight or slightly concave posterior margin in E. scoteina ; the cucullus is more prolonged in E. physalodes than in E. scoteina ; the digitate process is longer in E. scoteina than in E. physalodes ; the juxta lobes are different in their form as follows: mesial margin is S-shaped in E. physalodes , straight or neary evenly curved in E. scoteina ; mesial margin joins distal margin in a right angle in E. scoteina , in acute angle in E. physalodes ; distal margin has a straight, posteriorly directed extension that joins the valval process in E. scoteina ; there is ony short, laterally directed extension in E. physalodes .

Description. Forewing length 4.5–5.5 mm (n = 4 ♂). Labial palpus ascending, length 1.2 x diameter of head, white with apex of third segment grey above; below evenly fuscous grey except apex of second segment white. Head, scape, pedicel and neck tuft grey, mottled with darker tips of scales. Pecten formed of a few narrow, grey scales at the base of scape. Flagellum thick, leaden grey, annulated with dark grey rings. Foreleg varying from ochreous grey to dark, leaden grey, spurs ochreous; midleg ochreous grey with tibia and tarsomeres white distally. Hindleg ochreous grey, tarsomeres grey, distally pale. Forewing grey, densely mottled with darker grey tips of scales given the impression of forewing being leaden grey; plical spot dark grey, small and elongate, at middle of wing length at fold; discal spot similar, at 2/3 wing length in middle; fringe scales concolorous with forewing colour, shorter fringe scales distally dark grey forming indistinct fringe line along termen. Hindwing grey, fringe scales concolorous; underside of both wings grey with fringe scales concolorous.

Male genitalia. Uncus lobes medially separated by narrow, U-shaped incision; lobe twice as long as wide, somewhat tapered, distal margin rounded, ventral surface distolaterally with cylindrical scales arising from erect pinaculae. Basal arms of gnathos as long as uncus lobe, distally separate. Spinose knob of gnathos large, slightly tapered. Valva 3.5 x as long as wide, parallel-sided; basal fold of costa vestigial, distal fold narrow, extended to 5/6 length of valva; sacculus basally slightly concave, medially straight, distally slightly bent towards cucullus, without distal spine, joining cucullus without clear delimitation; cucullus rounded, bent towards costa. Digitate process 1/4 length of valva, straight, parallel-sided, distally blunt, with scales medially and setae distally. Median plate of juxta oval, concave without lateral or posterior extensions. Juxta lobe prolonged, medial margin basally curved, medially straight, distally with medially directed, acute-tipped lobe formed of medially extended distal margin distal margin straight, laterally extended; lateral margin straight, strongly sclerotized. Vinculum long, narrow U-shaped, without medial ridge. Phallus 8/9 length of valva, acute-tipped, broadest and evenly bent in basal half; insertion of ductus ejaculatorius dorsoposteriorly directed; caecum blunt, as long as width of basal opening of phallus; distal opening extended to distal 4/5 of phallus; in vesica no spinules or granules; cornuti absent.

Female genitalia. Unknown.

Biology. The collecting site is near an open maquis habitat (Holloway 1979). All other four species assigned to the E. gerasmia species complex by Kaila (2011) feed on Juncus spp. ( Juncaceae ), so this genus is a likely host candidate for E. scoteina .

Distribution. New Caledonia.

Etymology. The name is derived from the Greek word scoteinos, ‘darkness; gloom’. This refers to the wing colour of E. scoteina .

Figures

FIGURES 1 – 9. External appearanCe of Elachista spp. SCale 2 mm. 1. E. concubia sp. nov., ♂ holotype. 2. E. achlyodes sp. nov., ♂ holotype. 3. E. scoteina sp. nov., ♂ holotype. 4. E. cardiaca sp. nov., ♂ holotype. 5. E. dilobates sp. nov., ♂ holotype. 6. E. vespertina sp. nov., ♂ holotype. 7. E. cynopa MeyriCk (New Caledonia, Mt. DzumaC). 8. E. cynopa MeyriCk (Australia; ACT, BlaCk Mountain; a reared speCimen). 9. E. fugax sp. nov., ♂ holotype.

FIGURES 10 – 12. Male genitalia of Elachista spp. 10. E. concubia sp. nov., ♂ holotype. Left: general image of genitalia, phallus in same sCale. Right top: juxta and digitate proCesses. Right bottom: apex of phallus enlarged. 11. E. achlyodes sp. nov., ♂ holotype. Left: general image of genitalia, phallus in same sCale. Right top: juxta and digitate proCesses. Right bottom: apex of phallus enlarged. 12. E. scoteina sp. nov., ♂ holotype. Left: general image of genitalia, phallus in same sCale. Right top: juxta and digitate proCesses. Right bottom: phallus enlarged.