Nannopterix Gibbs

Gibbs, George W., 2010, establishment of five new genera from Australia, New Caledonia and New Zealand, Zootaxa 2520, pp. 1-48 : 41-42

Nannopterix Gibbs , gen. nov.

Type species: Nannopterix choreutes Gibbs , sp. nov., by present designation.

Diagnosis. An extremely small micropterigid ( Fig. 2 C) with reduced, probably non-functional mouthparts, mandible a small, non-toothed lobe; maxillary palps 4-segmented ( Fig. 3 H).

Description. Head interocular index 0.7. Ocelli present. Head capsule microtrichiated between ocellus and compound eye. Antennal scape and pedicel swollen but less so than in any other micropterigid ( Fig. 3 A), scape with no sign of indentation, pedicel longer than wide; ratios of scape:pedicel:first flagellomere are length = 2:1.5:1 and width = 1.5:1.2:1. Male with 34–37 antennal flagellomeres; each, including the first, moniliform, slightly longer than wide but with a concave distal end giving a compressed, shuttle-cock appearance; the first clothed with dense lamellar scales, remainder with whorls of long narrow fluted scales bearing prominent scutes, the scale density such that the underlying ascoids and true shape of the flagellomere is obscured. Ascoids characteristic of the Australian-group lineage of micropterigids occur on all flagellomeres beyond the first; ascoid branches strongly elbowed, with branches beyond the elbow extending distally to midway over adjacent flagellomere ( Fig 5 B); 12+ per ascoid at mid-antennal length. Mandibles present but reduced to a pair of short lobes, not meeting in mid-line, lacking teeth but with fine brush-like inner borders. Labial palps well-developed, 3-segmented. Maxillary palps ( Fig. 4 H) reduced to 4 segments, very short, only 0.45x head width at compound eyes; ratio about 1:0.8:1:1.4.

Tegulae and dorsum of thorax with closely fitting lamellar scales. Well-developed epiphysis present on fore-tibia.

Forewing venation as for Tasmantrix . Hindwing Sc unforked; a single frenular bristle.

Male abdomen and genitalia. ( Figs 15 A–E) Dorsum of A1 sclerite absent. S5 gland exit area of sabatincoid type; situated in middle of segment; raised on annulated prominence with 7–8 long fluted scales toward posterior side of peduncle, terminal cuticle around aperture with dense, tightly packed flattened papillae ( Fig. 6 G). T8 not reduced in size. S8 remnants present. Sclerite 9 equal in length to S6 along midventral line, encircling the segment but ‘open’ at mid-dorsal line; slightly thickened along antero-lateral margins. Valvae simple, curving upwards and lacking ornamentation apart from a field of unspecialised ‘retrosetae’ on inner surface toward apex. Tergum 10 wide, hood-like, slightly bilobed. Median plate short, peg-like with a small anterior laterally expanded fan. Anal cone with lateral sclerites. Phallus short; gonopore terminal, circular, occupying whole of phallus diameter, radial folds elongated dorsally to slightly overhang the gonopore; ventral bulb absent; phallocrypt densely clothed with long acutely pointed micro-scales.

Female. Unknown.

Larva. Unknown.

Etymology. Genus name derived from Latin nanno (dwarf) referring to the diminutive size of this micropterigid, the smallest known from the southern hemisphere with the ending -opterix in accord with other Australian-group genera.

Remarks. The monotypic species choreutes exhibits many features that set it apart from other micropterigids in the SW Pacific region. Nevertheless, it is clearly aligned with Zealandopterix , Aureopterix and Tasmantrix as part of the Australian-group in both morphological and molecular analyses. Of particular interest is the simplicity of the male genital morphology. All typical micropterigid components are present but without any specialised developments.

Figures

FIGURE 2. Adult moths from life: A, Austromartyria porphyrodes (Turner), female; B, A. porphyrodes feeding on dehiscing spores of Blechnum cartilagineum, at The Crater, Atherton Tableland; C, Nannopterix choreutes sp. nov., male; D, Aureopterix micans sp. n., male; E, Aureopterix sterops (Turner), female; (A, C – E to scale, white scale bars = 1 mm)

FIGURE 3. Antennal bases and maxillary palps. A – D: Scape, pedicel and 9 th flagellomere of: A, Nannopterix choreutes; B, Zealandopterix zonodoxa; C, Austromartyria porphyrodes; D, Sabatinca incongruella Walker. E – H: maxillary palps of: E, Austromartyria porphyrodes; F, Zealandopterix zonodoxa; G, Aureopterix micans; H, Nannopterix choreutes. Scale lines for A = 0.2 mm; for B, C, D = 0.4 mm; for E, F = 0.2 mm; for G = 0.2 mm; for H = 0.1 mm. fl: first flagellomere; sc: scape; pe: pedicel.

FIGURE 4. Wing venation: A, Austromartyria porphyrodes, male; B, ditto female hindwing; C, Tasmantrix calliplaca; D, Sabatinca incongruella. Vein nomenclature follows Kristensen (2003). Scale lines = 1 mm.

FIGURE 5. Scanning electron micrographs of antennal flagellomeres (at approx mid-length) to show ascoid sensilla: A, Austromartyria porphyrodes male; B, Nannopterix choreutes male; C, Tasmantrix calliplaca male; D, Aureopterix sterops male, E, Tasmantrix lunaris male, F, Tasmantrix lunaris male ascoid, viewed from distal end of flagellomere after detaching remainder of antenna. as, ascoid sensilla; sc, long fluted scale; ts, trichoid sensilla. Scale: white bars = 0.01 mm.

FIGURE 6. Glandular structures of Australasian Micropterigidae: A, costal margin of hindwing; B – H, abdominal segment 5 glands: A, Austromartyria porphyrodes, male showing glandular hairs; B, A. porphyrodes, male, with all but one piliform scale removed; C, Tasmantrix calliplaca, male; D, Tasmantrix calliplaca, female, with six piliform scales removed; E, Tasmantrix nigrocornis, male; F, detail of gland aperture of E; G, Nannopterix choreutes, male, with four piliform scales removed; H, Aureopterix sterops, male, with six piliform scales removed. Scale: white bars = 0.01 mm.

FIGURE 15. Nannopterix choreutes sp. nov. Genitalia: A – E. male: A, dorsal; B, lateral; C, ventral; D, phallus, lateral view; E, distal apex of phallus enlarged, lateral.