Flaviellus kluanensis Smith and Skelley, 2020

Flaviellus kluanensis Smith and Skelley View in CoL , new species

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Type Series. Holotype male ( Figs. 1–7 View Figs ) at CMNC labeled “ YUKON. Kluane N.P. / Sheep Mt. / 2.VI.1979 / G.G.E.Scudder ” (both metatarsomeres partially missing) . One male paratype at UBCZ labeled “ YT, Burwash / Landing / 14.vi. 1984 / J.Krebs ” (all legs badly damaged or missing, abdominal contents missing) . One male paratype at UBCZ labeled “ CAN, YT, Kluane L. / Emerald I. / 61.0209, -138.4893 / 24. VI. 2017, SEM Team” (right metathoracic leg and left metatarsomere missing). GoogleMaps One male paratype at RBCM labeled “ Canada; YT; Kluane Lake; 3 km S / of Cultus Bay ; 825-945m el.; / 61.1197° N 138.4222° W; dry, / SWfacing rock slopes. 7-Jun- / 2013 (SC/SS13-28). Cannings, / Sydney G.; Stotyn, Shannon” (both protibiae damaged and protarsomeres, right mesotibia, and mesotarsomere missing, left elytron missing) GoogleMaps .

Additional Specimen. A second specimen at UBCZ labeled “CAN, YT, Kluane L. / Emerald I. / 61.0209, -138.4893 / 24. VI. 2017, SEM Team” was also examined but excluded from the type series because of its poor condition. The head, pronotum, and most of the legs are missing.

Taxonomic Placement. In addition to the characters in Table 1 View Table 1 , this species is placed in the genus Flaviellus based on the following combination of character states. Head evenly convex, without tubercles; clypeus glabrous, weakly emarginate medially ( Fig. 4 View Figs ). Pronotum widest from middle to base, evenly convex, with weak lateral fringe of setae in dorsal view, dark brown with lighter markings in apical corners ( Figs. 1–2 View Figs ). Scutellum triangular, approximately one-eighth the length of elytra ( Fig. 1 View Figs ). Elytral surface smooth, evenly convex, glabrous, light brown with darker markings basally ( Figs. 1–2 View Figs ). Dorsal surface of protibia smooth, impunctate ( Fig. 5 View Figs ). Male protibial spur modified (thick and bent downward 90°) ( Fig. 5 View Figs ). Male inferior mesotibial spur unmodified. Meso- and metatibial apices fringed with long and short spinules. Metatarsomere 1 shorter than superior tibial spur, longer than metatarsomeres 2–3 combined.

Gordon and Skelley (2007) stated that the male metasternum (= metaventrite) is not deeply excavated and is without a patch of dense setae in Flaviellus . However, we observed that many (but not all) male specimens in all species in this genus have weak lateral rows of setae bordering a medially concave metaventrite. This character can be used as an aid in identifying the sex of all species in the genus.

Diagnosis. Flaviellus kluanensis is distinguished from the other species in the genus by the following combination of character states. Head and pronotum dark brown with light markings in the apical corners of the pronotum. Lateral pronotal margins evenly convex with the rest of the surface (not explanate). Lateral elytral margin fringed with setae shorter than scutellum near base. Protibia with basal half of outer edge serrate.

This new species will key out imperfectly to Flaviellus subtruncatus (LeConte) in couplet 1 of Gordon and Skelley’ s (2007) key to Flaviellus species, based on the dark brown head and pronotum. Flaviellus kluanensis is distinguished from F. subtruncatus by the paler apical corners of the pronotum (entire lateral edge paler in F. subtruncatus ), the sparse setation on the inner margin of the meso- and metatibiae (brush of long setae in F. subtruncatus ), the male protibial spur bent downward in apical half (bent near apex in F. subtruncatus ), and the apex of the male parameres thin and bend downwards 90° around a membranous (unsclerotized) fold ( Figs. 6–7 View Figs ) (apex very slightly curved downward and entirely sclerotized in F. subtruncatus ; see Gordon and Skelley 2007: fig. 656).

Holotype Description. Length 4.5 mm, width 2.0 mm. Color dark brown; head and pronotum with light brown markings in apical corners of pronotum ( Figs. 1–2 View Figs ); elytra light brown with slightly different shaded markings, elytral base dark brown. Dorsal surfaces shiny, smooth, completely glabrous, evenly convex without any indication of tubercles or depressions. Head: Densely punctate near apex (separated by less than 1 puncture diameter), moderately punctate on disc (separated by 1–4 puncture diameters), and sparsely punctate along base. Frontoclypeal suture almost imperceptible ( Fig. 4 View Figs ). Pronotum: With a sparse mixture of smaller and larger punctures, larger punctures increasing in density laterally. Pronotal lateral margins fringed with short setae in apical half. Elytra: Each with 9 distinct, punctate striae; interstrial surfaces impunctate to sparsely punctate with weak microsculpture. Lateral margin of elytron fringed with short setae near base. Elytral disc and declivity lacking setae. Legs: Protibia with 3 large teeth along outer edge, basal half of outer edge serrate; inner edge curved outward before insertion of apical spur ( Fig. 4 View Figs ). Protibial spur thick and bent downward 90° on apical half ( Fig. 5 View Figs ), lacking inner apical tooth. Meso- and metatibiae with short, sparse setae along inner margin. Mesotarsomere 1 and metatarsomere 1 longer than associated superior spur and longer than associated tarsomeres 2–3 combined. Venter: Prosternal peg (directly behind procoxae) erect perpendicularly with tuft of long setae. Metaventrite smooth, sparsely punctate, concave medially ( Fig. 3 View Figs ). Abdominal sternites and pygidium evenly setose. Genitalia: Paramere apex thin, bend downwards 90° around a membranous (unsclerotized) fold ( Figs. 6–7 View Figs ).

Variation. Paratypes range 4.0–5.0 mm in length. Dorsal coloration is sometimes darker with almost black head and pronotum and dark brown elytra. Some males have a row of setae on either side of the medial metaventral concavity. It is difficult to characterize the lateral fringe of setae on the pronotum and elytra and the finer detail of the legs because all specimens examined were abraded to some degree. No female specimens were observed.

Distribution. This species is only known from the area around Kluane Lake, in southwestern Yukon, Canada ( Fig. 8 View Fig ).

Etymology. The name is derived from the Kluane region where the entire type series was collected.

Natural History. Gordon and Skelley (2007) report that most species of Flaviellus are primarily psammophilous detritivores. However, recent collections of F. subtruncatus in New Mexico (P. Lago, personal communication) were in a wide variety of animal dung in high elevation meadows.

Comments. With the addition of two species to Flaviellus , the key to species in Gordon and Skelley (2007) needs to be modified as follows:

1. Lateral fringe of setae on pronotum short and indistinct in dorsal view; protibia with basal half of outer edge serrate .......... 1a

— Lateral fringe of setae on pronotum long and distinct in dorsal view; protibia with basal half of outer edge smooth ........... ......... 2 (see Gordon and Skelley 2007)

1a(1). Head and pronotum yellowish brown, occasionally with pale brown discal area, weakly contrasting with elytra; northcentral USA and adjacent Canada........ ............... F. consentaneus (LeConte)

— Head and pronotum mostly black, strongly contrasting with elytra ..................... 1b

1b(1a). Pronotum pale along entire lateral margin; male protibial spur bent downward near apex, with small inner apical tooth; southwestern USA: Arizona and New Mexico northward, east of Rocky Mountains to North Dakota................ ................ F. subtruncatus (LeConte)

— Pronotum pale only at apical angle; male protibial spur bent downward in apical half, lacking inner apical tooth; Canada: Yukon........................ F. kluanensis Smith and Skelley , new species