Diphtheroptila nix De Prins, Sruoga & Zwick, 2025

Prins, Jurate De, Hartley, Diana, Sruoga, Virginijus, Nicholls, James, Wallace, Jesse & Zwick, Andreas, 2025, Diversity of Australian Ornixolinae (Lepidoptera: Gracillariidae) with taxonomic and nomenclatural acts within the related taxa (Acrocercopinae and Gracillariinae) based on the evidence of museomics, bionomics, and mitogenomics, Zootaxa 5616 (1), pp. 1-340 : 113-116

Diphtheroptila nix De Prins, Sruoga & Zwick , sp. nov.

( Figs 150, 172, 173, 204, 205, 226, 227, 259, 638)

Type locality: Australia, Queensland, Kuranda .

Type specimen: Holotype ♂: [labels verbatim] [1] Australia Q. [Queensland]/Kuranda/nr. Cairns/em.[emerged] 22.xii.[December]1999/ T. Kumata leg. [2] Host 6215/ Glochidion / sp., DNA sample NULT025530, genitalia slide ANIC 6212 , ANIC Acc. no 31 085525, in ANIC (Canberra).

Type depository: Australian National Insect Collection , Canberra, Australian Capital Territory, Australia .

Diagnosis: This species is externally, by micromorphology and mitogenomics the closest to Diphtheroptila crotonella sp. nov. The holotype of Diphtheroptila nix sp. nov. was reared at the same spot, from the same host plant and at the same time of the year, under the same micro climatic conditions, even the day of emergence is the same. Diphtheroptila nix sp. nov. can be externally diagnosed from D. crotonella sp. nov. only by the shining white smooth frons characterizing D. nix sp. nov. while in D. crotonella sp. nov. the frons is light beige. External morphology, especially based on worn specimens is not diagnostic for this species clearly belonging to the rather compact Glochidion -feeding species group. Bionomics is not diagnostic either. This species was reared from the same Host (Herbarium number 6089) Glochidion sp. as D. crotonella sp. nov. The most reliable diagnostic characters are in the internal morphology (male genitalia) and in mitogenomics. The obvious diagnostic difference is in the shape of valvae. In D. nix sp. nov. they are more or less narrow, of equal width along their entire length, while in D. crotonella sp. nov. valvae are very broad especially in their mid-part and rather short.

Description: Wingspan ca. 5.7 mm; length of the forewing 3.2 mm ( Fig. 150).

Head ( Figs 172, 173): vertex covered with light beige ochreous smooth scales, directed anteriorly; occiput with two bunches of light beige short scales directed posteriorly. Frons shining white, covered by equally suppressed, long piliform scales, a dark fuscous line stretching on anterior margin of antennae and then continuing along both scapes is seen only from the frontal view; a tuft of dark fuscous long piliform scales just below antenna, next to the margin of eye, directed anteriorly. Maxillary palpus slightly longer than scape, straight, apical palpomere snowy white. Labial palpus relatively long, ca. 2× longer than the diameter of the eye, straight, basal palpomeres carry a long tuft of light ochreous long piliform scales of different lengths with longest situated at the basal part of palpomere II, apical palpomere with blunt apex, snowy white; proboscis dirty white. Antenna slightly longer than forewing, light ochreous, with silver metal apices, not ringed, ventrally creamy white, pedicel short, slightly smaller than the following flagellomere, concolourous with the following flagellomere, scape dirty white anteriorly and light fuscous posteriorly, pecten short, dirty white, arranged in a compact row.

Thorax ( Figs 150, 205): thorax and tegula light beige. Forewing narrowly elongated, equal in width along all its length, with a gently rounded apex, ground colour fuscous golden beige with ornamental pattern. First dorsal patch at base of forewing, followed by a group of three stripes at sub-base, the second group of dorsal markings, situated at the mid of forewing consists of two curved, irregularly shaped, narrow, but distinct fasciae; the following group of markings at sub-apex mirror the mid fasciae, beyond the midline of forewing meet an oblique costal stripe and form an angulate fascia, with a double lined base; the final marking is a narrow curved line just before the apex repeating the path of sub-apical fascia; black apical spot rather small but distinct; apical line very thin, dark fuscous, almost black, distinct. The fringe line smoothly follows apical part of forewing, stopping at tornal area; tornal area with short dirty white bunch of scales, which follow the fringe line. Fringe shining ochreous shorter at tornus the longest at sub-apical part and again shortening towards base of forewing. Hindwing narrow, elongate, sharply pointed, ground colour light beige with silver shine, fringe long, ca. 6× longer than the width of hindwing at the base, with the longest piliform scales hanging at the base of the dorsum of the hindwing. Foretibia dark fuscous with two light spots one at mid and the other at apical part; tarsomere I dark fuscous with white sub-apex, tarsomeres II–IV dirty white with fuscous apices, tarsomere V light grey with fuscous apex, tip of fore tarsus fuscous; mid femur light beige, mid tibia fuscous with irregular shaped dirty white patches, tibial spurs short, slightly shorter than tarsomere I, dark fuscous-dirty white patches; mid tarsomeres with fuscous bases and dirty white mid parts; hind femur pale beige, hind tibia light grey with golden shine and with a row of long erect impressive spines along tibia; median spurs long, as long as about 1/3 of tibia length, silver shining, apical spurs short, dirty white, tarsomeres dark fuscous with contrastive white apices, tip of hind tarsus dark fuscous.

Abdomen ( Fig. 204, 259): fuscous dorsally, genital segments fuscous with ochreous shading, sternites ventrally white with golden shine, four oblique dark brown stripes are present on lateral side of abdomen. Abdomen rather long and slender in comparing with other genera. Lateral margins of abdominal opening very strongly sclerotised, ventral crossing joint with narrowly sclerotised anterior margin that borders ventral sclerotised plate; sternal apodemes initiating at the sharp corners of abdominal opening are short, thin, hardly visible, act as tiny prolongations of lateral sclerotisations of abdominal opening, lightly bent, tergal lateral sides of the opening semi-round, there is no directly observable connection between left and right mirroring sides, each lateral side on tergum I is the initiating point of tergal apodemes, that have two short appendages at bases, and form an arrow-shaped sclerotised structure; tergal apodemes thin, straight, slightly approaching each other, rather long, reaching mid part of tergum II; apical part of tergal apodemes sharp. Anterior margins of segments III–VII narrowly and finely melanised.

Male genitalia ( Figs 226, 227): Tegumen broken, one left arm is present which is slightly shorter than valva; valvae symmetrical, comparatively narrow, of equal width along their entire length, with broadly rounded and heavily setose apices; costal margin of valvae broad and strongly sclerotised; sacculus with a marked sclerotisation; transtilla incomplete; vinculum is short but well developed, broad U-shaped, consisting of two fused symmetrical rectangular plates with clearly visible suture, saccus short but well developed V-shaped with narrow digitiform appendage. Aedeagus is ca. 1/3 shorter than valva, broad, thick, well developed with narrowing and pointed digitiform vesica, that carries two thick, sharp, situated at the angle 90° cornuti, body of aedeagus with broad irregular sclerotised band; coecum with irregular, rather big sclerotisation.

Female genitalia: No data.

Individual variation: Described from the holotype only.

Bionomics: Following the rearing data present in the ANIC collection this species is monophagous, feeding on an unidentified species of the plant genus Glochidion ( Phyllanthaceae ). Mining period presumably from mid till late December. Adults are active from late December.

Mitogenomic data: The species is maximally supported as sister to D. crotonella sp. nov. in all analyses ( Fig. 638).

Distribution: Known only from the type locality: Australia, Queensland, Kuranda.

Etymology: The specific name nix , meaning snow, white piliform scales, refers to the snowy white and tightly pressed frons. It is a noun of the feminine gender in nominative case in apposition.