Elachista fugax Kaila 2017, sp. nov.
Creators: name: Kaila, Lauri
Publisher: name: Zenodo
Year: 2017
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Lepidoptera
Elachistidae
Elachista
Elachista fugax

description: Elachista fugax sp. nov.
Figs 9, 17
Type material. Holotype ♂: New Caledonia, Mt. Koghis, 400 m, 12.–14.XI.1996, UV trap R. Brown & O. Pellmyr leg. Genitalia slide by L. Kaila, USNM 142,824 (USNM).
Diagnosis. Elachista fugax is a small species that does not resemble any other species known from New Caledonia. It is characterized by the dorsoventrally flattened head, an unusual trait which is otherwise present in Elachistinae in the E. saccharella and E. heteroplaca groups sensu Sugisima & Kaila (2005). The forewing pattern consists of dark brown longitudinal stripes and indistinct dark brown oblique band on mottled bluish-grey ground colour. As such it does not resemble any Australian species either. The male genitalia are generally similar to the Australian E. fucosa Meyrick, 1922. They are characterized by the rounded, ventrally directed uncus lobes, the broad digitate process, the pair of dorsally directed lateral lobes in the median plate of the juxta, the narrow vinculum and the presence of a small lobe at apex of the phallus. Externally these species are quite different, E. fucosa being a very narrow-winged species. E. fucosa is characteristic with the extraordinarily long saccus and phallus, which is almost 1.5 x as long as the valva. The phallus is shorter than valva in E. fugax, and the vinculum + saccus is not nearly as long as in E. fucosa (cf. Fig. 282 in Kaila 2011).
Description. Forewing length 2.6 mm. Labial palpus ascending, length 1.2 x diameter of head, above bluish white, below powdered with dark grey-tipped scales. Head somewhat dorsoventrally flattened, frontoclypeus white, vertex covered with grey, dark brown-tipped scales. Scape below white, above as well as pedicel, patagium and thorax covered with grey, dark brown-ttipped scales. Pecten absent. Foreleg inwardly pale, outwardly leaden grey; mid- and hindlegs inwardly pale, outwardly white, tibia and tarsomeres distally grey; spurs pale. Forewing ground colour formed of basally bluish grey and distally darker brown scales giving a strongly mottled appearance, fold dark brown from base to middle of wing length; another similar streak at apical third of wing; indistinctly delimited group of dark grey scales near costa in middle of wing length, another, small group somewhat distad of the costal group at dorsal margin, these patches forming indistinct, oblique band; fringe scales grey, at apex partly white; shorter broad fringe scales dark brown-tipped forming dark brown fringe line along termen; hindwing dark grey. Underside of both wings dark grey, scales along termen of forewing with faint, dark fringe line and distally paler grey scales.
Male genitalia. Uncus lobes ventrally directed, widely separate from each other, rounded, ventrolateral surface with long hair-like scales. Tegumen dorsomedially incised, nearly meeting the margin of uncus. Spinose knob of gnathos large, rounded. Valva broadest basally, evenly tapered towards apex; length 4 x its width at base; basal fold of costa narrow, extended 3/5 length of valva, distal fold strongly sclerotised, extended to 4/5 length of valva where cucullus twisted on top; cucullus rounded; sacculus slightly bent medially, otherwise straight, without distal spine. Digitate process 1/4 length of valva, broad, parallel-sided, blunt distally, with setae. Median plate of juxta with pair of large, flat, dorsally directed pockets in lateral margin; juxta lobe parallel-sided, distal margin convex, with small group of setae in the middle; medial margin joining distal margin without an angle. Vinculum V-shaped, without median ridge, tapered to long and narrow saccus. Phallus 0.9 x the length of valva, narrow, basally slightly bent; caecum very short; apex with small sclerotized plate; vesica without cornuti or spine groups.
Biology. The single known specimen has been collected by UV trap. Otherwise biology is unknown.
Distribution. New Caledonia.
Etymology. The Latin word fugax, ‘swift’ refers to the typical habit of running fast, of moths of the E. freyerella group.
Remarks. E. fugax is in many respects similar to the Australian E. fucosa Meyrick, 1922. With E. fucosa ¸it shares the same character combination used in the phylogenetic analyses by Kaila (1999a): the tegumen is dorsally incised and medially meets the uncus; uncus lobes are ventrally directed; these charaters are typical of the E. freyerella group. The presence of lateral, dorsally directed lateral lobe in the median plate of the juxta and the absence of lobe on caecum are plesiomorphic traits. The ‘crown’ species have the median plate of juxta formed as dorsally directed, inflated single lobe (Kaila 1999a, b, Kaila & Sugisima 2011). On the basis of this evidence this species is sister to the lineage has formerly been considered as the genus Cosmiotes Clemens, 1860.
description: Published as part of Kaila, Lauri, 2017, First records of Elachistinae from New Caledonia: evidence of repeated dispersal events with Australia (Lepidoptera, Gelechioidea, Elachistidae), pp. 536-550 in Zootaxa 4300 (4) on pages 546-547, DOI: 10.11646/zootaxa.4300.4.4, http://zenodo.org/record/839266