Gilesdytes vixsulcatus (Baehr & Main, 2016)

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

Gilesdytes vixsulcatus (Baehr & Main, 2016) Figs 38-39

Type locality.

WA, Pilbara, Marillana Creek, c. 85 km NNW Newman, 22°41'53.30"S, 119°20'28.80"E.

Material examined.

1 ♂, WA, Pilbara , 90 km NW of Newman, near Yandi mining area, Ministers North deposit, 22°49'26.54"S, 119°05'23.89"E (WGS84), 20 Feb. 2009, P. Bell, G. Perina, Trap, (BHP010-EXR1154-MNL:7056) Western Australian Museum Entomology Reg. no. 82619 (WAM) .

Note.

Baehr and Main (2016) description of this species is based on only one female specimen. They assigned the genus Gracilanillus based on the presence of inconspicuous longitudinal grooves at the base of elytra. The study of a male morphologically comparable to the habitus drawing provided by Baehr and Main (2016) and collected from a locality close to the Gracilanillus vixsulcatus type locality, allowed the description of the male of this species, and also the clarification of the taxon’s systematics. Based on some characters considered fundamental in the Anillini taxonomy ( Giachino 2005; Giachino and Vailati 2011), the species is here assigned to Gilesdytes gen. nov.

Differential diagnosis.

Small species (TL mm 1.29), easily distinguishable from G. ethelianus sp. nov. by the discal pore located towards the elytral edge, and from G. pardooanus sp. nov. by the lateral edge of the pronotum smooth, non-denticulate, near the basal angle.

Description of the ♂.

TL 1.29 mm. Body elongated, depigmented, yellow-testaceous; integument shiny, with evident microsculpture, and covered with sparse and relatively long pubescence.

Head relatively large, narrower than the pronotum. Labium bearing a median tooth. Antennae short, robust, moniliform, just exceeding the base of the pronotum when stretched backwards. Fronto-clypeal furrow slightly distinct; subrectilinear anterior margin of epistome.

Pronotum subrectangular, slightly transverse (max. width / max. length ratio = 1.04), maximum width at the anterior third, very wide basal border, slightly wider than anterior border. Pronotum sides anteriorly poorly arcuate, posteriorly subrectilinear, gently convergent, and laterally smooth, non-denticulate, but distinctly emarginated before the base. Anterior angles rounded, not prominent; posterior angles not protruding externally, rounded at the vertex. Disc slightly convex, with sparse and relatively long pubescence; median groove very shallow, slightly marked. Marginal groove relatively wide and flat, much enlarged near the base; anterior marginal setae inserted inside the marginal groove, approximately on the anterior third; basal setae inserted approximately on the posterior angles.

Legs long and slender, with metatrochanters normal and metafemora unarmed. Males with two dilated protarsomeres without adhesive phanerae.

Elytra subrectangular, very elongated (max. length/max. width ratio = 1.94), maximum width at the anterior 7th, not emarginated before apex. Disc poorly convex; integument shiny, with evident microsculpture and relatively long, sparse, upright pubescence. Humeri marked, almost right; post-humeral margin denticulate, with distinct crenulations up to the base of the apical 5th of the elytron; elytral apices not separately rounded. Marginal groove wide and evident up to the 8th pore of the umbilicate series.

Chaetotaxy: scutellar pore large, foveate. Umbilicate series with 1st, 2nd, and 3rd pores of the humeral group not equidistant, 2nd and 3rd pores closest; 4th pore clearly farther from the 3rd one and placed at the end of the basal third of the elytron; 5th pore placed just after the middle length of the elytron; 5th and 6th pores spaced out ca. 1/3 of the distance from 6th and 7th; 7th, 8th, and 9th pores almost equidistant and slightly displaced onto the disc, 8th pore placed after the 9th one. A single discal seta placed laterally towards the edge of the disc and located between the 7th and 9th pores.

Aedeagus (Fig. 39 ) relatively small, median lobe long, slender, subrectilinear, with evident basal bulb; ventral margin poorly and gently curved from the basal bulb to the apex; apical blade evident, but short. Endophallus with a median, sinuate, sclerified phanera. Left paramere slender and very elongated, reaching the distal fifth of the median lobe, and bearing two setae; right paramere shorter than the left one.

Female. See Baehr and Main (2016).

Distribution.

Gilesdytes vixsulcatus is known from two localities approximately 85-90 km NW of Newman, Pilbara, WA. The distance between the two collection points is ca. 30 km.

Figures

Figures 38 - 42. Gilesdytes gen. et spp. nov., habitus (38, 40, 41) aedeagus in lateral view (39, 42) 38, 39 G. vixsulcatus (Baehr and Main), ♂ 40 G. pardooanus sp. nov., HT ♀ 41, 42 G. ethelianus sp. nov., HT ♂. Scale bars: 0.1 mm.