Eurylychnus blagravei ( Castelnau, 1867 )

Lay, Stuart, 2023, A taxonomic review of the Australian genus Eurylychnus Bates (Coleoptera: Carabidae: Broscini), Zootaxa 5330 (2), pp. 247-264 : 249-252

Eurylychnus blagravei ( Castelnau, 1867)

( Figs. 2A , 4A–C , 7A )

Mecodema blagravii Castelnau, 1867: 75 . Putzeys 1868: 323 (description and transfer to Percosoma ). Sloane 1892: 51–52

(description and transfer to Eurylychnus ). Moore et al. 1987: 120 (catalogue). Häckel et al. 2010: 65 (checklist). Percosoma mastersi Rainbow, 1899: 148 . Synonymised by Moore 1960: 174. Type locality: Mt Kosciusko, NSW.

Type material: Syntypes Mecodema blagravii: Blagravii Cast [handwritten] // Mont. di. Victoria. Coll. Castelnau [handwritten and typed, black label border] // Blagravii Cast [typed] // Typus [typed, red font with red label border] ( MCG) [examined photographs]; Mont. di Victoria Coll. Castelnau [handwritten and typed, black label border] ( MCG) [examined photographs]; Mont. di Victoria. Coll. Castelnau [handwritten and typed, black label border] ( MCG)[examined photographs] . Syntype (s) of Percosoma mastersi in the Australian Museum, Syndey, not examined.

Other material examined (31): New South Wales: (1), 10km SW Braidwood by Shoalhaven River , 4.v.1986, C. Reid ( ANIC); (1) , Cooma , xi.1956, Sedlacek, ( ANIC); (1) , Kosciusko , i.1906, H.J. Carter ( MV) [ COL7436 ]; (1) , Mount Kosciusko , ii.1962, G.T. Coulson ( ANIC); (1) , Mount Kosciusko , i.1931, C. Oke ( MV) [ COL7437 ]; (1) , Tumut River , 1600m, 21.ix.1957, Sedlacek ( ANIC) ; Australian Capital Territory: (1), Piccadilly Circus , 5.i.1979, J.F. Lawrence & D. Rentz ( ANIC); (1) , Piccadilly Circus, Brindabella Range , 29.x.1982, J.T. Doyen coll. ( ANIC) ; Victoria: (1), Australian Alps , i.1940, C. Oke ( MV) [ COL7435 ]; (1) , Bogong High Plains , Pitfall open heath, 29.x.2008, M.A. Nash ( ANIC); (1) , Buln Buln East , 11.ix.1961, C.G.L Gooding ( ANIC); (1) , Carters Mill, Mansfield , 21.xii.2014 ( SLC); (1) , Gould , x.1959, G.T. Coulson ( ANIC); (2) , Moe , 9.viii.1945, C.G.L. Gooding ( ANIC); (1) , Mount Buller , i.2009, S. Lay ( SLC); (1) [♀], Mount Stirling, 2.xii.2021, S. Lay ( SLC); (3) , Mount Stirling, Craig’s Hut , 30.xii.2014 ( SLC); (4) [2 ♀, 1 ♁, 1 unknown sex], Mount Stirling, Razerback Hut , 23.xii.2020, S. Lay ( SLC); (1) , Omeo , i.1925, F. E. Wilson ( MV) [ COL7441 ]; (1) , Ringwood , 20.ix.1919, F.E. Wilson ( MV) [COL-7440]; (1), Snowy River , 10.iv.1947, Nat.Mus.Party ( MV) [ COL7434 ]; (1) , Tyres [Tyers] River , x.1960, G.T. Coulson ( ANIC); (1) , Tyres [Tyers] River , ix.1960, G.T. Coulson ( ANIC); (1) , Warragul , viii.1959, F.E. Wilson ( MV) [ COL7439 ]; (1) , Whisky Flat, Vic Alps Road , 20.ii.1951, B. Givan ( MV) [ COL7438 ] .

Diagnosis: Eurylychnus blagravei is similar in size to E. regularis and E. cylindricus , however E. blagravei can be distinguished by only having 7 striae on the elytra, with the 4 th stria beginning at the humeral angle. Furthermore, in E. blagravei the posterior angles of the pronotum are more constricted and have pronotal tubercles on the margins of the basal angles ( Fig. 2A ). Eurylychnus blagravei is sympatric with E. dyschirioides , but E. blagravei can be recognised by its larger body length (> 16.5mm), and by having only 1 seta on either side of the pronotum, which contrasts with the 3–5 setae on either side of the pronotum in E. dyschirioides .

Redescription: Body shiny black, legs red to reddish black, mouthparts and antennae dark piceous to black. Body length 16.5–22.3mm; maximum pronotum width 5.0–7.0mm; maximum elytra width 5.7–7.6mm.

Head: Vertex smooth, with sparse minute micropunctures. Transverse impression behind the eyes strong or weak. Frontal impressions strongly defined, curving inwards from the eyes, joining the frontoclypeal suture and continuing forward with a weaker impression on the clypeus, where it terminates in a seta before the anterior margin. Clypeus anterior margin straight to weakly emarginated. Labrum anterior margin moderately to weakly emarginated, with 6 evenly spaced setae. Eyes with 1 supraorbital seta each. Mandibles with a seta in the scrobe. Mentum median tooth broad, short and bifid with a seta each side of the base; paramedian fovea present; lobes broad and round. Submentum with 2 setae. Stipes with 2 setae each, the inner seta more than double the length of the outer. Gula convex with some wrinkles; gular sutures with small gular pits.

Thorax: Pronotum covered with sparse minute micropunctures, becoming reticulation of fine meshes on lateral margins; sometimes with transverse wrinkles from median impression; foveae present adjacent to the basal angles; margins strongly constricted posteriorly to base, with tubercles on basal angles; pronotum widest at approximately the midline, with 1 seta on the lateral margins at or below the midline; median impression weak, extending from the anterior margin and terminating just before the posterior margin; pronotal carina borders the lateral margins, extending onto the beginning of the anterior margins and terminating posteriorly at the basal angles. Prosternum convex, smooth or with some transverse wrinkles, anterior margin with a raised border. Protrochanters with 1 seta each. Male protarsi without squamose setae on ventral surface. Metatrochanters with a seta. Mesocoxae with or without a seta. Metacoxae with 1 seta on anterior margin.

Elytra: Elytral disc convex and oval; covered in reticulation of fine meshes, sometimes confined to the edges of each interstice in the apical half of the elytra; lateral elytral carina extending from humerus to apex. Parascutellar striole isolated from striae 1, but weaker than other striae. Elytra with 7 striae, striae 1–6 strongly defined, striae 7 faint; stria 4 begins at the humeral angle and striae 3 and 4 diverge basally; interstices weakly convex; striae without obsolete punctures. Basal groove usually with 2–3 obsolete asetose punctures on each side of the suture. Humerus simple.

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

Male genitalia: Aedeagus left paramere ( Fig. 4A ) broad, asetose, constricting to a broad denticle at apex; right paramere ( Fig. 4B ) long, narrow, gently tapering from apical half to form a pointed apex, with short setae present on the apical half of the ventral margin. Median lobe ( Fig. 4C ) strongly ventrally curved, moderately deflected to the right; apex rounded.

Figures

FIGURE 2. Dorsal habitus of A, Eurylychnus blagravei; B, Eurylychnus cylindricus; C, Eurylychnus regularis; D, Eurylychnus victoriae. Scalebars are 2mm.

FIGURE 4. Male genitalia of Eurylychnus blagravei (A–C): A, left paramere, B, right paramere, C, median lobe left lateral; E. cylindricus (D–F): D, left paramere, E, right paramere, F, median lobe left lateral; E. regularis (G–I): G, left paramere, H, right paramere, I, median lobe left lateral; E. victoriae (J–L): J, left paramere, K, right paramere, L, median lobe left lateral. Scale bars are 0.5mm.

FIGURE 7. A, Eurylychnus blagravei, with parascuttelar striole isolated from striae 1; B, Eurylychnus victoriae, with parascuttelar striole joined to apical portion of striae 1.