Scydmaenus (Scottiscydmaenus) clarkianus Franz
Creators: name: Jałoszyński, Paweł
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Staphylinidae
Scydmaenus
Scydmaenus clarkianus

description: Scydmaenus (Scottiscydmaenus) clarkianus Franz
Scydmaenus (Scottiscydmaenus) clarkianus Franz, 1975: 278.
(Figs 125–134, 155, 159, 200)
Type material studied. Holotype (AUSTRALIA: WESTERN AUSTRALIA): ♂ (Fig. 130), with labels illustrated in Fig. 200: “Perth / J. Clark ” [brownish, handwritten], “ Scydmaenus / (Scottiscydmaenus) / clarkianus m. / det. H.Franz ” [white, handwritten and printed], “Typus” [red, handwritten], “SAMA Database / No. 25-037033” [white, printed], “SAMA Digital Image / 21. Aug 2013 ” [green, printed and handwritten] (SAMA).
Paratypes (39 exx.). WESTERN AUSTRALIA: 21 exx. mounted on 3 large cardboards, 7 on each, on one pin, with additional card with 4 ants (most likely Brachyponera lutea), “Swan R. / J. S. Clark” [white, printed], “ Scydmaenus / (Scottiscydmaenus) / clarki {sic!} m. / PARATYPUS ” [yellow, handwritten and printed], “SAMA 25- 43072” [white, printed] (SAMA; another mounting card with 4 specimens originally on the same pin was pinned separately during the current study and labelled “Swan R. / J. S. Clark” [white, printed], “part of / SAMA 25- 43072” [white, printed]— 3 specimens on the left are Scydmaenus sp. [not S. clarkianus], one specimen on the right is Scydmaenus mirus Franz); 1 ♀, “Swan R. / W Australia / J. Clark” [white, handwritten], “ ♀ ” [white, printed], “ Scydmaenus / (Scottiscydmaenus) / clarkianus m. / PARATYPUS ” [yellow, handwritten and printed], “SAMA 25- 43082” [white, printed] (SAMA); 1 ♀, with Brachyponera lutea, “Swan R. / W Australia / J. Clark” [white, printed], “ Scydmaenus / Pubesc much shorter / than in optatus / not-microps and has / 4jnt club” [brownish, handwritten], “ Scydmaenus / (Scottiscydmaenus) / clarkianus m. / PARATYPUS ” [yellow, handwritten and printed], “SAMA 25- 43075” [white, printed] (SAMA); 1 ♀, with unidentified ants,, “Swan R. / W Australia / J. Clark” [white, printed], Scydmaenus / (Scottiscydmaenus) / clarkianus m. / PARATYPUS ” [yellow, handwritten and printed], “SAMA 25- 43080” [white, printed] (SAMA); 1 ♀, “Swan R. / W Australia / J. Clark” [white, handwritten], “ ♀ ” [white, printed], “ Scydmaenus / (Scottiscydmaenus) / clarkianus m. / PARATYPUS ” [yellow, handwritten and printed], “SAMA 25- 43083” [white, printed] (SAMA); 1 ♀, with Brachyponera lutea, “Swan R. / W Australia / J. Clark” [white, handwritten], “ ♀ ” [white, printed], “ Scydmaenus / (Scottiscydmaenus) / clarkianus m. / PARATYPUS ” [yellow, handwritten and printed], “SAMA 25- 43078” [white, printed] (SAMA); 6 exx. on 4 cards on one pin, with Brachyponera lutea, “Swan R. / J. S. Clark” [white, printed], “SAMA 25- 43079” [white, printed] (SAMA; another mounting card with 3 specimens originally on the same pin was pinned separately during the current study and labelled “Swan R. / J. S. Clark” [white, printed], “part of / SAMA 25-43079” [white, printed]—specimen on the left is Scydmaenus sp. [not S. clarkianus], specimen in middle and on the right are Scydmaenus mirus Franz); 1 ♀, “Swan R. / W Australia / J. Clark” [white, handwritten], “ ♀ ” [white, printed], “ Scydmaenus / (Scottiscydmaenus) / clarkianus m. / PARATYPUS ” [yellow, handwritten and printed], “SAMA 25- 43076” [white, printed] (SAMA); 1 ex., with Brachyponera lutea, “Swan R. / W Australia / J. Clark” [white, handwritten], “ Scydmaenus / (Scottiscydmaenus) / clarkianus m. / PARATYPUS ” [yellow, handwritten and printed], “SAMA 25- 43081” [white, printed] (SAMA); 1 ♀, with Brachyponera lutea, “Swan R. / W Australia / J. Clark” [white, handwritten], “ Scydmaenus / (Scottiscydmaenus) / clarkianus m. / PARATYPUS ” [yellow, handwritten and printed], “SAMA 25- 43084” [white, printed] (SAMA); 3 exx. mounted on one card, “Perth / J. Clark” [brownish, handwritten], “ Scydmaenus / microps Lea / Id. by A.M. Lea” [brownish, handwritten], “ Scydmaenus / (Scottiscydmaenus) / clarkianus m. / PARATYPUS” [yellow, handwritten and printed], “SAMA 25- 43070” [white, printed] (SAMA); 1 ♀, “Perth / W Australia / J. Clark” [white, handwritten], “ Scydmaenus / (Scottiscydmaenus) / clarkianus m. / PARATYPUS ” [yellow, handwritten and printed], “SAMA 25- 43074” [white, printed] (SAMA).
Additional material studied. WESTERN AUSTRALIA: 1 ♂, originally mounted together on one card with specimens identified here as S. brachyponerophilus sp. n., during present study separately mounted and pinned on original short pin, with white printed copy of original locality label “Swan R. / W Australia / J. Clark”, and with one of two original labels “ Scydmaenus / optatus Sharp / Id. by A. M. Lea” [white, handwritten and printed], and “part of SAMA 25- 43099” [white, printed] (SAMA).
Specimens excluded from type series of S. clarkianus (13 exx.): 4 exx. mounted on one card and originally pinned as a part of SAMA 25-43072 (see above)— 3 specimens on the left are Scydmaenus sp. [not S. clarkianus], one specimen on the right is Scydmaenus mirus Franz) (SAMA); 3 exx. mounted on one card and originally pinned as a part of SAMA 25-43079 (see above)—specimen on the left is Scydmaenus sp. [not S. clarkianus], specimen in middle and on the right are Scydmaenus mirus Franz); 3 exx. mounted on one card, SAMA 25-43085 (from Swan River), all Scydmaenus mirus (SAMA); 1 ex. of Scydmaenus mirus, with unidentified ants, from Swan River, SAMA 25-43077 (SAMA); 1 ex. of Scydmaenus mirus, with unidentified ants, from Perth, SAMA 25-43086 (SAMA); 1 ex. of Scydmaenus mirus, “with Euponera lutea ”, from Swan River, SAMA 25- 43071; 1 ♂ designated here as holotype of Scydmaenus brachyponerophilus, from Swan River, SAMA 25-43073 (SAMA).
Revised diagnosis (based on males). Head clearly elongate (Fig. 155); profemoral tooth at most right-angled, broader than long or as long as broad (Fig. 159); length of temple in dorsal view about 4 × as long as eye (Fig. 155); aedeagus in dorsal view (Fig. 131) almost gradually narrowing from sub-basal region to truncate and weakly concave apical margin.
Redescription. Body in male (Fig. 130) strongly convex, elongate and slender, BL 1.85–1.93 mm; pigmentation uniformly light to dark brown (including appendages); cuticle moderately glossy, covered with vestiture of setae slightly lighter than body.
Head (Figs 125–126, 155) in dorsal view elongate and rounded, broadest at eyes, HL 0.35–0.38 mm, HW 0.31– 0.34 mm; vertex and frons confluent and weakly convex, posterior margin of vertex arcuate and weakly anteriorly concave; tempora about 4 × as long as length of eye in dorsal view; supraantennal tubercles indistinct; frons over antennal fossae broadly subtriangular and with blunt, broadly subtriangular anterior margin. Eyes conspicuously small, almost circular, not emarginate posteriorly. Punctures on frons and vertex fine, inconspicuous; setae (including those on tempora) short, sparse, nearly recumbent. Genae (Fig. 126) as sparsely setose as frons and vertex. Anterior (exposed) region of head capsule demarcated from neck region by short abrupt impression around occipital constriction, anterior margin of gular plate on neck region with indistinct, narrow anteriorly-directed projection. Submentum (Fig. 126) without submental lobes; hypostomal ridges (Fig. 126) extend mesally and anteriorly to connect at middle behind anterior margin of submentum where they form distinct transverse carina. Antennae (Figs 127, 130) long and slender, AnL 1.03–1.05 mm; three terminal antennomeres forming club, but antennomere 9 is so slender that club appears as dimerous; scape 3 × as long as broad, distinctly broadening distally; pedicel slightly more than twice as long as broad; antennomeres 3 and 4 each twice as long as broad, 5 2.5 × as long as broad, 6–8 each about twice as long as broad, 9 2.5 × as long as broad, gradually broadening distally, 10 nearly twice as long as broad and distinctly broadening distally but again narrowing in short distal region, 11 much shorter than 9 and 10 combined, about 2.2 × as long as broad, nearly symmetrical.
Pronotum in dorsal view (Fig. 125) elongate, broadest near anterior third, PL 0.50–0.58 mm, PW 0.43–0.48 mm; anterior margin nearly straight; anterior corners weakly marked, obtuse-angled and blunt; sides strongly rounded in anterior half; posterior corners barely marked; posterior margin weakly arcuate; posterior marginal carina obliterated. Pronotal disc covered with fine and shallow, unremarkable sparse punctures; setae similar to those on head, moderately dense and long, suberect. Ventrally (Fig. 126) prothorax with nearly asetose and impunctate hypomera and basisternal region only slightly longer than procoxal rests, sparsely covered with moderately long recumbent setae, with short and relatively indistinct anterior ‘collar’, and with distinct vestiges of notosternal sutures visible as notches on sides of anterior prothoracic margin; hypomeral ridges distinct and complete, demarcating narrow inner (adcoxal) region of each hypomeron, anteriorly running along procoxal rests and connecting at middle to form biarcuate anteprocoxal carina demarcating basisternal region posteriorly.
Elytra (Figs 125, 130) slightly rhomboidal, broadest at or slightly behind of middle, EL 0.98–1.03 mm, EW 0.65–0.70 mm, EI 1.43–1.58. Humeral calli, basal impressions and basal foveae lacking; apices separately rounded. Elytral punctures fine and inconspicuous; setae similar to those on pronotum, moderately dense. Hind wings completely reduced.
Mesoventrite (Fig. 128) with carinate subrectangular mesoventral intermesocoxal process posteriorly fused with elongate and posteriorly broadening anterior metaventral process, fusion site indistinctly marked on surface by transverse ridge. Metanepisterna (Fig. 128) completely fused with metaventrite, but fusion site marked on surface as line along which sides of thorax are bent dorsally. Metaventral intermetacoxal process (Fig. 128) broad and short, with distinctly concave posterior margin, its lateral portions form short subtriangular processes weakly projecting posteriorly; distance between metacoxae subequal to 1/3 width of metaventrite at its posterior margin (excluding metanepisterna) and slightly wider than one metacoxa. Metaventrite (Fig. 128) weakly convex, slightly flattened at middle, unmodified and covered with sparse, short, slightly suberect setae.
Legs (Figs 126, 128–130, 159) long and slender; profemur with short, broad and relatively blunt distal tooth (Fig. 159) slightly variable within studied specimens, but never elongate; protibia (Fig. 129) slightly broadened distally; protarsus with barely discernibly broadened proximal half and tarsomeres 1–3 covered ventrally with dense setae, of which only a few have spatulate adhesive tips. Protarsomere 1 nearly twice as long as broad, 2–4 each indistinctly elongate, 5 about 3 × as long as broad; mesotarsi longer than protarsi, mesotarsomere 1 about 3 × as long as broad, tarsomeres 2–4 each weakly elongate, tarsomere 5 about 2.5 × as long as broad; metatarsi slightly longer than mesotarsi, metatarsomere 1 3 × as long as broad, tarsomeres 2–4 each weakly elongate, tarsomere 5 about 3 × as long as broad.
Aedeagus (Figs 131–134) elongate and slender, AeL 0.58 mm, in dorsal view median lobe broadest near base, narrowing distally toward truncate apex, apical margin slightly concave, with lateral groups of minute setae; flagellum broadened in proximal region to form three consecutive symmetrical chambers; ostium situated in distal half of median lobe, far from its apex.
Female. Externally differs from male in profemora lacking teeth. BL 1.83–1.95 mm; HL 0.35–0.38 mm, HW 0.31–0.33 mm, AnL 0.95–1.03 mm; PL 0.50–0.55 mm, PW 0.41–0.48 mm; EL 0.98–1.05 mm, EW 0.70–0.75 mm, EI 1.37–1.45.
Distribution. Known only from SW Australia: SW Western Australia (vicinity of Perth).
Remarks. Scydmaenus clarkianus is distinct in the slender body, elytra strongly narrowing anteriorly, conspicuously small eyes, and a broad and short profemoral tooth. The long type series was found to be composed of four species; in addition to S. clarkianus it also contains specimens of Scydmaenus (Heteromicrus) mirus Franz, 1975 (in fact three times as many as the type series of S. mirus includes!), a new species of Scottiscydmaenus described below as S. brachyponerophilus, and specimens of an undetermined species of Scydmaenus.
description: Published as part of Jałoszyński, Paweł, 2023, Scydmaenus Latreille of Australia: Revision of species in subgenera Choleropsis Franz, Kingius Franz, Mascarensia Franz, Parallomicrus Franz, Scottiscydmaenus Franz, and description of Ascydmaenus subgen. n. (Coleoptera, Staphylinidae, Scydmaeninae), pp. 1-75 in Zootaxa 5371 (1) on pages 50-54, DOI: 10.11646/zootaxa.5371.1.1, http://zenodo.org/record/10144644