Heterobathmia nielsenella, Hünefeld, Frank & Kristensen, Niels P., 2012

Hünefeld, Frank & Kristensen, Niels P., 2012, Two new heterobathmiid moth species with distinctive female genital configurations (Lepidoptera: Heterobathmiidae), Zootaxa 3281, pp. 61-68 : 66

Heterobathmia nielsenella n. sp.

Material examined: Holotype Ƥ: ARGENTINA: Neuquen [Province] [sta.] 24, S. C. de Bariloche, Cerro Lopez 1300 m, 11.x.1981, Nielsen & Karsholt (genitalia preparation NPK 1083). Paratypes: ARGENTINA: Neuquen, 24 S. C. de Bariloche, Cerro Otto 930 m, 12.x.1981, Nielsen & Karsholt (2Ƥ). All in Natural History Museum of Denmark. Wing and body vestiture well preserved in holotype, moderately to poorly preserved in paratypes.

Diagnosis. Distinguishable from females of the other described Heterobathmia species by the paramedian concavities of the apical part of the subgenital plate and, in particular, by the prominent forward extension of the dorsal surface of the latter and its continuation into a sizable apodemal plate, both traits being without counterparts in the genus. Distinctive white forewing markings diagnostic in well-preserved specimens ( Fig. 1 B).

Description: Only females known. A medium-sized Heterobathmia species, forewing length ≈ 4.3 mm.

Wings: Forewing ground colouration light brown with some purplish iridescence. As in H. megadecella the silvery-white scaling is more extensive than in the previously described species. When well preserved, this forms somewhat distinctive markings: elongate basal spots behind C and M+CuA-stem, respectively; costal spot before pterostigma, tornal spot, central spot before M-CuA cross vein; large subtriangular subapical spot; as in H. megadecella white scales seem absent from an (otherwise well preserved) area around the Rs-M1 crossvein and M1/M2 fork. Hindwing grey with weak iridescence. In marginal ‘fringes’ of both wing pairs silvery-white piliform scales form prominent spots around R-Rs1 and M2.

Female genitalia ( Fig. 4 ): Subgenital plate (sclerotized venter VIII plate) ≈ 1.5–1.7x length of tergum VIII; distal part with paired depressions (observable in dried specimens, Fig. 4 A) flanking the apex. Dorsal sclerotization of terminal unit (i.e., dorsum IX+X) with area of unmelanized cuticle along mid-line. Apophyses from anterolateral corners ≈ 0.14–0.18x dorsolateral length of terminal unit. Sclerotized upper wall of subgenital plate extending far forwards into segment VIII, eventually continuing forwards into a broad unsclerotized apodemal lamella ( Fig. 4 B).

Distribution: Known from just two localities in Neuquen Province near S. C. de Bariloche ( Argentina).

Phenology and bionomics: Adults were collected on two consecutive October dates. See also notes under H. megadecella above.

Etymology: This is the only Heterobathmia species recognized so far which was not given a preliminary name by the late Ebbe S. Nielsen, and we make a point of associating his name with this outstandingly interesting moth genus, to the understanding of which he made significant contributions.

Figures

FIGURE 1. Heterobathmia habitus. A, H. megadecella male holotype; B, H. nielsenella, female holotype.

FIGURE 4. Heterobathmia nielsenella n. sp., female postabdomen. A, stacked multifocus photographs of abdominal apex of intact holotype, lateral view, notice paramedial depressions in subgenital plate along its smooth-textured (shiningl) apical part; B, lateral view, slide preparation of paratype (as Fig. 3 B). la, prominent cuticular lamellar continuation of upper wall of subgenital plate.