Gracilanillus pannawonicanus, Giachino & Eberhard & Perina, 2021

Giachino, Pier Mauro, Eberhard, Stefan & Perina, Giulia, 2021, A rich fauna of subterranean short-range endemic Anillini (Coleoptera, Carabidae, Trechinae) from semi-arid regions of Western Australia, ZooKeys 1044, pp. 269-337 : 269

Gracilanillus pannawonicanus sp. nov. Figs 6-7

Type locality.

WA, Pilbara, 11 km SSE of Pannawonica, Robe Valley, Mesa K Mine, 21°43'11"S, 116°15'43"E.

Type series.

HT ♀, WA, Pilbara, 11 km SSE of Pannawonica, Robe Valley, Mesa K Mine, (bore MEK1701), 21°43'11"S, 116°15'43"E (GPS), 10 June-3 Aug. 2006; litter trap L. Mould, M. Greenham; Western Australian Museum Entomology Reg. no. 64215 (WAM).

Differential diagnosis.

Gracilanillus pannawonicanus sp. nov. can be distinguished from G. hirsutus for the presence of a short and dense pubescence on the elytral disc, not directly longitudinally aligned, for the absence of excess setae on the head, and for the position of the ninth pore of the umbilicate series, which is placed quite forward, before the end of the elytral groove.

Description of the HT ♀.

TL 1.43 mm. Body elongated, depigmented, yellow-testaceous; shiny integument with evident microsculpture and pubescence.

Head robust, almost hypertrophic, slightly narrower than pronotum, excess setae absent. Labium toothless, articulated mentum. Antennae robust, moniliform, short, not exceeding the base of the pronotum when stretched backwards. Fronto-clypeal furrow indistinct; anterior margin of the epistome subrectilinear.

Pronotum subquadrate (max. width / max. length ratio = 1.07), maximum width at the basal anterior third, and basal border as wide as anterior border; sides slightly but regularly arcuate from anterior to posterior angles, strictly sinuate just before basal angles. Anterior angles rounded, slightly prominent; posterior angles subsquare and acuminate at vertex. Disc convex, with short and very sparse pubescence; median groove very shallow, hardly evident. Marginal groove wide and flat, slightly enlarged near the base; anterior marginal setae placed inside the marginal groove, almost on the anterior fifth; basal setae nearly before posterior angles.

Legs short and stout, with metatrochanters short and stout and metafemora non dentate (Fig. 7 ).

Elytra subrectangular, elongated (max. length / max. width ratio = 1.95), with maximum width in the middle, not emarginated in preapical zone. Disc slightly convex, with evident longitudinal groove running more or less between the scutellar pore and the 2nd discal pore; integument shiny, with evident microsculpture, and short, very dense, and upright pubescence, not longitudinally aligned. Humeri well marked but rounded; post-humeral margin denticulate, with distinct crenulation up to the apical fourth; elytral apices separately and acutely rounded. Marginal groove wide and evident almost all the way to the 8th pore of the umbilicate series.

Chaetotaxy: scutellar pore large, foveate. Umbilicate series with the first three pores of the humeral group equidistant; 4th pore farther and placed at the end of the basal third of the elytron; 5th pore placed before the apical third of the elytra; 5th and 6th ones spaced out ca. half of the distance between 6th and 7th; 8th slightly displaced onto the disc; 7th and 8th slightly closer to each other than the 8th and 9th; 9th pore of the umbilicate series placed well forward (compare to the standard position). Two discal setae, first placed just after the 5th pore of the umbilicate series, second one placed just after the 8th pore.

Male. Unknown.

Etymology.

The name of the species derives from the town Pannawonica near the type locality Mesa K Mine, in the Pilbara region.

Distribution.

Gracilanillus pannawonicanus sp. nov. is known so far only from the type locality Mesa K Mine, in the Robe River Valley, 11 km SSE of Pannawonica, Pilbara, WA.

Figures

Figures 4 - 7. Gracilanillus spp.: habitus HT ♀ (4, 6) left metafemur and metatrochanter in ventral view HT ♀ (5, 7) 4, 5 G. hirsutus sp. nov. 6, 7 G. pannawonicanus sp. nov. Scale bars: 0.1 mm.