Euconnus vexillus, Caterino, 2022

Caterino, Michael S., 2022, First report of the Euconnus Thomson subgenus Cladoconnus Reitter in the New World, represented by thirteen new Appalachian species (Coleoptera, Staphylinidae, Scydmaeninae), ZooKeys 1137, pp. 133-175 : 133

Euconnus vexillus sp. nov.

Figs 2B , 4 , 5

Type material.

Holotype ♂, deposited in FMNH: "USA:SC: Greenville Co. 35.1523°N, 82.2814°W, Chestnut Ridge Heritage Preserve, vi.05.2015, S. Myers, Hardwood litter" / "[QR code] CLEMSON ENT CUAC000026944". Paratypes (10, CUAC, FMNH) - 2 ♂, 2 ♀: same data as type; 1 ♂, 1 ♀: "USA:SC: Greenville Co. 35.1518°N, 82.2839°W, Chestnut Ridge Heritage Preserve, vi.05.2015, S. Myers, Hardwood litter"; 1 ♀: "USA:SC: Greenville Co. 35.1501°N, 82.2820°W, Chestnut Ridge Heritage Preserve, vi.05.2015, S. Myers, Hardwood litter"; 2 ♀: "USA:SC: Greenville Co. 35.1406°N, 82.2790°W, Chestnut Ridge Heritage Preserve, vi.05.2015, S. Myers, Hardwood litter"; 1 ♀: "USA:SC: Greenville Co. 35.1506°N, 82.2799°W Chestnut Ridge Heritage Preserve, iv.08.2018, M. Caterino & L. Vásquez-Vélez, sifted litter".

Other material.

(26) WV: Mercer Co., Camp Creek State Forest , 23-Jul-1971, leaf litter (4 ♂, 11 ♀) ; ' Black Mts' , x.1901 (3 ♂) ; NC: Caldwell Co., Grandfather Mt. State Park , Nuwati Trail, 4020 ft., 17-May-2021 (1 ♂) ; McDowell Co., Pisgah National Forest , Mackey Mountain Trail, 3433 ft., 25-Aug-2015 (2 ♂) ; McDowell Co., Pisgah National Forest , Snooks Nose Trail, 1998 ft., 25-Aug-2015 (3 ♀, 1 ♂) ; Polk Co., Green River Game Lands, 1740 ft., 18-Mar-2018 (1 ♂) .

Diagnostic description.

This species is very similar to the preceding species and can best be distinguished by male genitalic and antennal characters. Like the preceding, males are winged, while females appear not to be. A few noteworthy external differences can also be cited: males with distinct carinae on antennomeres VIII and IX (Fig. 4E ); female antennae less distinctly tetramerous, with antennomere VIII intermediate in size between antennomeres VII and IX (Fig. 4D ); body darker, stout, with only faintly rufescent elytral humeri, most distinctly lighter along posterior half of elytral suture; male eyes smaller, less protuberant, with only ~ 25 ommatidia; median basal carina of pronotum slightly better developed to base (Fig. 4F ); aedeagus (Fig. 2B ) with median lobe broadly truncate at apex; parameres short, tapered, bearing three apical setae; compressor plate strongly asymmetrical, rather short; endophallic armature with strong pair of upper processes: the left long and strongly hooked apically, with a thin inner laminar blade, its inner edge concave; the right shorter, more strongly curved toward middle of longer process; lower endophallic armature consisting of three hook-like processes of varying lengths, the lateral-most rather short and strongly curved, the medial-most of intermediate length, the one between them the longest, its tip just visible between bases of upper processes (in ‘dorsal’ view).

Distribution.

This species has been found at several widely scattered localities east and northeast of the Asheville Depression, from the headwaters of the French Broad near the southern end of its range, at Chestnut Ridge, South Carolina, to southern West Virginia in the northeast. Most of its occurrences are at middle elevations, from 1090 to 4020 ft, most below 2000.

Remarks.

This species is similar and, judging by male genitalia, closely related to E. megalops . Both have similar opposing hooked upper endophallic sclerites, though the shorter right one (Fig. 2B ) of E. vexillus is distinctive. Moreover, the lower trio of endophallic sclerites are quite distinct in E. vexillus , with three hooks projecting distad to varying lengths. In males, the carinae of antennomeres VII and IX will immediately distinguish this species from E. megalops , and the only weakly tetramerous club of females can be used to distinguish most of those, although they are similar to darker females of E. adversus .

This species name means 'standard (or flag)- bearer’, referring to its possession of Cladoconnus -typical carinae, borne proudly on its antennae.

Figures

Figure 2. Aedeagus A Euconnus megalops B Euconnus vexillus C Euconnus cumberlandus D Euconnus vetustus.

Figure 4. Habitus and character photos of Euconnus vexillus A male, dorsal view B female, dorsal view C SEM of mouthparts, ventral view D SEM of female head, lateral E SEM of male antenna, lateral F SEM of elytra and pronotum G SEM of meta- and mesoventrites.

Figure 5. Map of collecting records for Euconnus (Cladoconnus) vexillus (squares), E. (C.) vetustus (stars), and E. (C.) adversus (circles).