Scydmaenus (Scottiscydmaenus) brachyponerophilus Jałoszyński 2023, sp. n.
Creators: name: Jałoszyński, Paweł
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Staphylinidae
Scydmaenus
Scydmaenus brachyponerophilus

description: Scydmaenus (Scottiscydmaenus) brachyponerophilus sp. n.
(Figs 150–154, 158, 162, 204)
Type material studied. Holotype (AUSTRALIA: WESTERN AUSTRALIA): ♁ (Fig. 150), with labels illustrated in Fig. 204: “Swan R. / J. S. Clark ” [white, printed], “with Ponera / lutea” [red, handwritten], “ Scydmaenus / (Scottioscydmaenus {sic!}) / clarkianus m. / PARATYPUS” [yellow, handwritten and printed], “SAMA 25- 43073” [white, printed], “ SCYDMAENUS / (SCOTTISCYDMAENUS) / brachyponerophilus m. / P. Jałoszyński, 2023 / HOLOTYPUS” [red, printed] (SAMA). Paratypes (13 exx.). WESTERN AUSTRALIA: 13 ♁♁, “Swan R. / W Australia / J. Clark ” [white, printed], “ Scydmaenus / optatus Sharp / Id. by A. M. Lea ” [white, handwritten and printed], “SAMA 25- 43099” [white, printed], originally all on one pin but on 3 large mounting cards, remounted during present study and currently each on separate card, on 3 pins (5, 4 and 4 specimens on each), one pin (with 5 specimens) with original labels, two remaining pins with white printed copies of original labels, one of them also with large unidentified ant (SAMA).
Diagnosis (based on males). Head clearly elongate (Fig. 158); profemoral tooth distinctly elongate and with sharp-angled apex (Fig. 162); length of temple in dorsal view slightly more than 3 × as long as eye; aedeagus in dorsal view (Fig. 151) almost gradually narrowing from sub-basal region to truncate and straight apical margin.
Description. Body in male (Fig. 150) strongly convex, elongate and slender, BL 2.05–2.33 mm; pigmentation uniformly light to dark brown (including appendages); cuticle moderately glossy, covered with vestiture of setae slightly lighter than body.
Head (Figs 150, 158) in dorsal view elongate, broadest at eyes, HL 0.38–0.43 mm, HW 0.35–0.40 mm; vertex and frons confluent and weakly convex, posterior margin of vertex arcuate and weakly anteriorly concave; tempora about 3 × 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. 150) long and slender, AnL 1.05–1.15 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; antennomere 3 nearly 2.5 × as long as broad, 4 about twice as long as broad, 5 about 2.5 × 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. 150) elongate, broadest near anterior third, PL 0.60–0.73 mm, PW 0.50–0.60 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. 150) slightly oval and slightly more narrowing anteriorly than posteriorly, broadest near middle, EL 1.05–1.15 mm, EW 0.75–0.93 mm, EI 1.27–1.44. 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 (Figs 150, 162) long and slender; profemur with elongate and acute distal tooth (Fig. 162), slightly variable within studied specimens, but in each of them elongate and with sharp-angled apex; protibia (Fig. 150) 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 about twice as long as broad, tarsomere 5 about 3 × as long as broad.
Aedeagus (Figs 151–154) elongate and slender, AeL 0.53 mm, in dorsal view median lobe broadest near base, narrowing distally toward truncate apex, apical margin straight, with lateral groups of minute setae; flagellum broadened in proximal region to form three consecutive symmetrical chambers; ostium situated between half and distal third of median lobe, far from its apex.
Female. Unknown.
Distribution. Known only from SW Australia: SW Western Australia (vicinity of Perth: Swan River).
Etymology. The adjective brachyponerophilus refers to the association of this species with the ant Brachyponera lutea.
Remarks. Specimens of this new species were found within material misidentified as S. clarkianus and S. optatus. Scydmaenus brachyponerophilus and S. clarkianus have almost identical aedeagi; the only difference is the straight apical margin in dorsal view in S. brachyponerophilus vs. weakly concave in S. clarkianus. However, externally they differ in the body silhouette (S. brachyponerophilus is less slender), body length (S. brachyponerophilus is larger), and, first of all, in the shape of the profemoral tooth in males. Scydmaenus brachyponerophilus has the profemoral teeth clearly longer and more acute than any other Australian species of Scottiscydmaenus.
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 59-62, DOI: 10.11646/zootaxa.5371.1.1, http://zenodo.org/record/10144644