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

description: Scydmaenus (Scottiscydmaenus) swanensis Franz
Scydmaenus (Scottiscydmaenus) swanensis Franz, 1975: 279.
(Figs 145–149, 157, 161, 203)
Type material studied. Lectotype (here designated) (AUSTRALIA: WESTERN AUSTRALIA): ♁ (Fig. 145), with labels illustrated in Fig. 203: “Swan R. / J. S. Clark ” [white, printed], “with Euponera / lutea” [white, handwritten], “ Scydmaenus / (Scottiscydmaenus) / swanensis m. / det. H.Franz ” [white, handwritten and printed], “ Typus ” [red, handwritten], “SAMA Database / No. 25-037024” [white, printed] (SAMA). Paralectotypes (18 exx.): WESTERN AUSTRALIA: 1 ♁, 1 ♀ on separate cards but on one pin, with ants, probably Brachyponera lutea, “Swan R. / J.S. Clark ” [white, printed], “ Scydmaenus / (Scottiscydmaenus) / swanensis m. / PARATYPUS ” [yellow, handwritten and printed], “SAMA 25- 43089” [white, printed] (SAMA); 1 ♀ (but identity not certain), with two large unidentified ants, “ Swan R. / W Australia / J. Clark ” [brownish, printed], “Inquiline” [pink, printed], “Lea has not / 5-11-18” [pink, printed and handwritten], “ Scydmaenus / (Scottoscydm. {sic!}) / swanensis m. / PARATYPUS” [yellow, handwritten and printed], “SAMA 25- 43091” [white, printed] (SAMA); 1 ♁, “Swan R. / W Austr. / J. S. Clark ” [white, handwritten], “with Eupo- / nera lutea” [white, handwritten], “ Scydmaenus / (Scottoscydm. {sic!}) / swanensis m. / PARATYPUS ” [yellow, handwritten and printed], “SAMA 25- 43092” [white, printed] (SAMA); 14 exx. mounted on two large cards (7 exx. on each), with 9 large unidentified ants of various sizes and shapes, “Swan R. / J. S. Clark ” [white, printed], “ Scydmaenus / (Scottoscydm. {sic!}) / swanensis m. / PARATYPUS” [yellow, handwritten and printed], “SAMA 25- 43090” [white, printed] (SAMA).
Specimens excluded from type series of S. swanensis (2 exx.): ♁ of Scydmaenus clarkianus Franz, Swan River, SAMA 25-43087; ♁ of Scydmaenus clarkianus Franz, Swan River, SAMA 25-43088. These specimens do not bear typical Franz’s “ PARATYPUS ” labels, instead their identification labels read only “Scottioscydm. {sic!} swanensis” in Franz’s hand; also the plastic cards with aedeagi can be recognized as typical of Franz. Therefore, Franz studied these specimens at the time of preparing the description of S. swanensis and, if correctly identified, they would be a part of the type series.
Revised diagnosis (based on males). Head as long as broad, round (Fig. 157); profemoral tooth at most right-angled, broader than long or as long as broad (Fig. 161); length of temple in dorsal view about 2.5 × as long as eye; aedeagus in dorsal view (Fig. 146) narrowing from sub-basal region distally and then slightly broadening in subapical area, apical margin truncate.
Redescription. Body in male (Fig. 145) strongly convex, elongate and moderately slender, BL 2.13–2.15 mm; pigmentation uniformly light to dark brown (including appendages); cuticle moderately glossy, covered with vestiture of setae slightly lighter than body.
Head (Figs 145, 157) in dorsal view as long as broad and rounded, broadest at eyes, HL 0.35–0.38 mm, HW 0.40 mm; vertex and frons confluent and weakly convex, posterior margin of vertex arcuate and weakly anteriorly concave; tempora about 2.5 × 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 small, almost circular, not emarginate posteriorly. Punctures on frons and vertex fine, inconspicuous; setae (including those on tempora) short, sparse, nearly recumbent. Genae 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. Antennae (Fig. 145) 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 about twice as long as broad; antennomere 3 slightly more than twice as long as broad, 4 about twice as long as broad, 5 nearly 3 × as long as broad, 6 slightly more than twice as long as broad, 7 and 8 each about 1.5 × as long as broad, 9 slightly more than twice as long as broad, gradually but weakly broadening distally, 10 about 1.5 × 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. 145) elongate, broadest near anterior third, PL 0.63–0.68 mm, PW 0.50–0.55 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 prothorax with nearly asetose and impunctate hypomera and basisternal region only slightly longer than procoxal rests, sparsely covered with moderately long recumbent setae.
Elytra (Fig. 145) evenly oval, broadest at or slightly in front of middle, EL 1.13 mm, EW 0.83–0.88 mm, EI 1.29–1.36. 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.
Legs (Fig. 145) long and slender; profemur with short, broad and relatively blunt distal tooth (Fig. 1161), slightly variable within studied specimens, but invariantly not elongate; protibia (Fig. 145) weakly 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 1.5 × as long as broad, 2–4 each about as long as broad, 5 about 3 × as long as broad; mesotarsi longer than protarsi, mesotarsomere 1 about 3 × as long as broad, tarsomeres 2–4 each about 1.5 × as long as broad, tarsomere 5 about 3 × as long as broad; metatarsi slightly longer than mesotarsi, metatarsomere 1 2.5 × as long as broad, tarsomeres 2–4 each nearly twice as long as broad, tarsomere 5 about 3 × as long as broad.
Aedeagus (Figs 146–149) elongate and slender, AeL 0.60 mm, in dorsal view median lobe broadest near base, narrowing distally and then again weakly broadening in subapical region toward truncate apex, apical margin sinuate laterally and with shallow median notch, with lateral groups of minute setae; flagellum broadened in proximal region to form three consecutive symmetrical chambers; ostium situated in slightly more than distal third of median lobe, far from its apex.
Female. Externally differs from male in profemora lacking teeth. BL 2.08–2.23 mm; HL 0.35–0.38 mm, HW 0.38–0.40 mm, AnL 0.88 mm; PL 0.60–0.63 mm, PW 0.50–0.53 mm; EL 1.13–1.23 mm, EW 0.83–0.88 mm, EI 1.13–1.23.
Distribution. Known only from SW Australia: SW Western Australia (vicinity of Perth: Swan River).
Remarks. Franz (1975) in the original description only mentioned “many specimens” of this species that he studied, and despite only one being labeled with his typical red “Typus” card, it cannot be regarded as a holotype. The type series was, therefore, composed of syntypes, and designation of a lectotype is necessary to fix a name-bearing type.
Scydmaenus swanensis and S. optatus have the heads as long as broad, in contrast to those in S. clarkianus and S. brachyponerophilus sp. n., which are slightly elongate. In S. swanensis the head is particularly short, almost round, with eyes larger than those in S. optatus. While the profemoral teeth in males of these two species are similar (and slightly variable, so slightly different shapes than illustrated in Figs 160–161 can be found), the aedeagi clearly differ. In S. swanensis, the distal region of the median lobe in dorsal view (Fig. 146) is distinctly slenderer than that in S. optatus (Fig. 136), and the apical margin has a different shape.
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 57-59, DOI: 10.11646/zootaxa.5371.1.1, http://zenodo.org/record/10144644