Eurylychnus kershawi Sloane, 1915

Lay, Stuart, 2023, A taxonomic review of the Australian genus Eurylychnus Bates (Coleoptera: Carabidae: Broscini), Zootaxa 5330 (2), pp. 247-264 : 258-259

Eurylychnus kershawi Sloane, 1915

( Figs 3C , 5G–I )

Eurylychnus kershawi Sloane, 1915: 445 . Moore et al. 1987: 121 (catalogue). Häckel et al. 2010: 66 (checklist).

Type material: Lectotype, here designated: Nat. Mus. Victoria, Wilson Prom, J.A.K., 1.12 [handwritten and typed] // 804 [blue label, handwritten] // Eurylychnus kershawi Sl. Type [handwritten] // Eurylychnus kershawi Sl. HOLOTYPE, PJD [red label, handwritten and typed] ( ANIC) [Darlington placed a holotype label on the specimen but did not publish that action]. Paralectotypes, here designated: (1), Wilsons Prom (ty?), Easter, 1912, J.a.K. // Eurylychnus kershawi, Sl. [back of label]: Det by Sloane 6.13 // Type [red label] // T-11822 Eurylychnus kershawi SYNTYPE [red label] ( MV); (1), Wilsons Prom (ty?), Easter. 1912, J.a.K. // 742 Eurylychnus kershawi Sl. Det by Sloane 6.13 // Cotype [blue label] // T-11823 Eurylychnus kershawi SYNTYPE [red label] ( MV).

Other material examined (17): Victoria: (1), Fish Creek , v.1944, C. Oke ( MV) [COL-3598]; (1), Tarra Valley , iv.1945, C. Oke ( ANIC); (1) , Wilsons Promontory, R. Blackwood ( MV) [COL-3597]; (1), Wilsons Promontory , ii.1916 J.U[?] Kershaw ( MV) [COL-3599]; (7) [3 ♁, 3 ♀, 1 unknown sex], Wilsons Promontory NP, Mount McAlister , ~ 400m, 10.ii.2021, S. Lay ( SLC); (6) [4 ♁, 1 ♀, 1 unknown sex], Wilsons Promontory NP, Mount Ramsay , ~ 400m, 11.ii.2021, S. Lay ( SLC) .

Diagnosis: Eurylychnus kershawi can be recognised from all mainland Eurylychnus species by having a smooth, glossy elytra with striae that are almost indistinct. The dorsal lustre of E. kershawi is similar to E. femoralis , however in E. kershawi the sides of the prontoum are straight before the posterior angles ( Fig. 3C ), in contrast to E. femoralis where they are sinuate before the basal angles. Furthermore, the medial expansion of the profemorae and raised anterior margins of the prosternum are far less pronounced in E. kershawi than in E. femoralis .

Redescription: Body glossy black; legs black; tarsi, mouthparts and antennae piceous. Body length 12.9– 13.6mm; pronotum maximum width 3.8–3.9mm; elytra maximum width 4.6–4.7mm.

Head: Vertex sometimes weakly convex, covered in minute micropunctures. Transverse impression behind the eyes strong. Frontal impressions starting at the anterior end of the eyes, curving inwards anteriorly to unite with frontoclypeal suture in a broad depression at the tentorial pits and continuing in a broad shallow grove halfway down the clypeus, ending with a seta. Clypeus moderately emarginated. Labrum moderately to strongly emarginated with 6 evenly spaced setae on the anterior margin, the outer setae longer than the inner 4. Eyes with a single supraorbital seta. Mandibles with a seta in the scrobe. Mentum tooth short and bifid with a seta at the base either side; paramedian fovea present; lobes broad and round. Submentum with 2 setae. Stipes with 2 setae, the inner being more than double the length of the outer. Gula weakly convex, sometimes wrinkled; gular sutures and gular pits almost indistinct.

Thorax: Pronotum covered in minute micropunctures; lacking foveae at the basal angles; pronotum base with a broad, weak impression, its lateral margins sloping upwards to the median impression; posterior 1/3 of lateral margins straight and angled inwards, with obsolete tubercles on the basal angles; pronotum widest slightly above the midline, with a single seta on the lateral margins at or above the midline; median impression not extending to the anterior margin, terminating at the broad basal impression posteriorly; pronotal carina borders lateral margins, beginning slightly onto the anterior angles, terminating at the basal angles. Prosternum convex and smooth, weakly bordered anteriorly. Protrochanters with 1 seta. Male protarsi lacking squamose setae on ventral surface. Profemorae lightly to moderately expanded medially, more pronounced in males. Metatrochaters with or without a seta. Mesocoxae and metacoxae both with 2 setae.

Elytra: Elytral disc narrow and convex; surface smooth, lacking reticulation of fine meshes; lateral elytral carina bordering margins from humerus to apex. Elytra with 8 striae that are faint to indistinct, sometimes with faint obsolete punctures. Basal groove without obsolete punctures. Humerus with a reflexed tooth pointed posteriorlaterally.

Abdomen: Ventrites 3–5 each with a pair of paramedian setae. Apical margin of ventrite 6 with a pair of paramedian setae.

Male genitalia: Aedeagus left paramere ( Fig. 5G ) broad, asetose, constricting dorsally to form a denticle; right paramere ( Fig. 5H ) long, thin, constricted in apical half with setae along the ventral margin of the apical half. Median lobe ( Fig. 5I ) strongly to moderately curved ventrally, slightly deflected to the right; apex blunt and rounded.

Figures

FIGURE 3. Dorsal habitus of A, Eurylychnus dyschirioides; B, Eurylychnus ovipennis; C, Eurylychnus kershawi; D, Eurylychnus femoralis. Scalebars are 2mm.

FIGURE 5. Male genitalia of Eurylychnus dyschirioides (A–C):A, left paramere, B, right paramere, C, median lobe left lateral; E. ovipennis (D–F): D, left paramere, E, right paramere, F, median lobe left lateral; E. kershawi (G–I): G, left paramere, H, right paramere, I, median lobe left lateral; E. femoralis (J–L): J, left paramere, K, right paramere, L, median lobe left lateral. Scale bars are 0.5mm.