Eurylychnus femoralis Sloane, 1915

Lay, Stuart, 2023, A taxonomic review of the Australian genus Eurylychnus Bates (Coleoptera: Carabidae: Broscini), Zootaxa 5330 (2), pp. 247-264 : 256-258

Eurylychnus femoralis Sloane, 1915

( Figs. 3D , 5J–L )

Eurylychnus femoralis Sloane, 1915: 446 . Moore et al. 1987: 121 (catalogue). Häckel et al. 2010: 66 (checklist).

Type material: Holotype: Mt Horror Tas , O. S. Adams from Lea. [handwritten] // Lea 11576 [blue label, handwritten] // Eurylychnus femoralis Sl. Type [handwritten] // Eurylychnus femoralis Sl . HOLOTYPE, PJD [red label, handwritten and typed] [specimen glued to triangle point] ( ANIC) .

Other material examined (11): Tasmania: (1) [♀], Denison Gorge ( ANIC); (2) [1 ♁, 1 ♀], Mount Barrow , 28.iii.1969, B.P. Moore ( ANIC); (7) [1 ♁, 1 ♀, 5 unknown sex], Mount Barrow , 28.iii.1969, B.P. Moore ( ANIC); (1) , Mount Barrow , 28.iii.1969, B.P. Moore ( ANIC) .

Diagnosis: The highly pronounced medial expansion of the profemorae separates E. femoralis from all other Eurylychnus species. The glossy and smooth elytra of E. femoralis make it similar to E. kershawi , but in E. femoralis the posterior sides of the pronotum are sinuate before the basal angle ( Fig. 3D ), unlike in E. kershawi where the posterior sides of the pronotum are straight before the basal angles. Eurylychnus femoralis is the only Eurylychnus species to occur in Tasmania although it could be confused with the similar looking Chylnus ater , for which E. femoralis differs by having a seta in the scrobe of the mandibles, having only 1 seta either side of the pronotum and by sides of the pronotum being sinuate before the basal angles.

Redescription: Body glossy black, legs black, mouthparts dark piceous to piceous, antennae dark piceous. Body size 13.2–14.5mm; maximum pronotum width 3.8–4.1mm; maximum elytra width 4.6–5.1mm.

Head: Vertex covered in minute micropunctures. Transverse impression behind the eyes strong. Frontal impressions beginning from the eyes, curving inwards and uniting on the frontoclypeal suture, continuing down the clypeus, ending at a seta on the lateral margins of the clypeus. Tentorial pits broad. Clypeus moderately emarginate. Labrum straight to weakly emarginate, with 6 setae on its dorsal anterior margin, the outer 2 slightly longer than the inner 4. Eyes with a single supraorbital seta. Mandibles with a seta present in the scrobe. Mentum tooth short, bifid, with a seta each side basally; paramedian fovea present; lobes broad and rounded. Submentum with 2 setae. Stipes with 2 setae, the inner being more than double the length of the outer. Gula moderately to weakly convex, with transverse wrinkles; gular sutures with small almost indistinct gular pits.

Thorax: Pronotum covered in minute micropunctures that increase in density on lateral margins; fovea weak and broad, beginning slightly above the basal angle; margins constricted posteriorly from basal 1/3, becoming slightly sinuate before the basal angles; basal angles with a small tubercle on margins; pronotum widest at the midline, with a single seta on the lateral margins at approximately the midline; median impression weak, not reaching the anterior or posterior margins; pronotal carina strong, bordering the lateral margins from the beginning of the anterior margin, terminating at the tubercles on the basal angles. Prosternum convex, with a raised narrow border. Protrochanters with a single seta. Males without squamose setae on ventral surface of protarsi. Profemorae expanded medially. Metatrochanters with or without a seta. Mesocoxae with 1–2 setae. Metacoxae with 2 setae.

Elytra: Elytral disc oval, convex laterally; surface smooth, lacking reticulation of fine meshes; lateral carina extending from humerus to apex. Parascutellar striole not isolated from stria 1. Elytra with 8 obsolete striae; stria 5 begins on the humeral angle; interstices flat; striae sometimes with irregular punctures. Basal groove without obsolete punctures. Humerus raised, with a broad tooth.

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. 5J ) broad, asetose, constricting at apex to form a short blunt denticle; right paramere ( Fig. 5K ) longer than left, thin, tapering in apical half to form a long, narrow, blunt apex. Short setae present on the ventral margin, from the apical half to apex, continuing slightly onto the dorsal margin at the apex. Median lobe ( Fig. 5L ) moderately curved ventrally, slightly deflected to the right; apex broad 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.