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

description: Scydmaenus (Choleropsis) beechmonti Franz
Scydmaenus (Cholerus) beechmonti Franz, 1975: 289.
(Figs 7–19, 51–52, 58–59, 70, 190)
Type material studied. Holotype (AUSTRALIA: QUEENSLAND): ♂, labels illustrated in Fig. 190: “Plateau s Bechmont / Queensld.,Austr. / lg. H.Franz 1970” [white, printed], “ Scydmaenus / (s.str.) {sic!} / beechmonti m. / det. H.Franz ” [white, handwritten and printed], “Typus” [red, handwritten], “♂” [white, printed], “ SAMA Database / No. 25-037022” [white, printed], “ SAMA Digital Image / 20.8. 2013 ” [green, printed and handwritten] (SAMA). Paratypes (3 exx.): QUEENSLAND: 1 ♀, “ Tamborine Mt. / Queensld.,Austr.” [white, printed], “ Scydmaenus / (Cholerus) / beechmonti m. / PARATYPUS” [yellow, handwritten and printed], “ SAMA 25- 43060” [white, printed] (SAMA); 1 ♂, “ Tamborine Mt. / Queensld.,Austr.” [white, printed], “ Scydmaenus / (Cholerus) / beechmonti m. / PARATYPUS ” [yellow, handwritten and printed], “ SAMA 25- 43061” [white, printed] (SAMA); 1 ♀, “Mt. Tambourine / Q.; A. M. Lea ” [white, printed], “ Scydmaenus / (Cholerus) / beechmonti m. / PARATYPUS ” [yellow, handwritten and printed], “ SAMA 25 - 43059” [white, printed] (SAMA).
Additional material studied (88 exx.): NEW SOUTH WALES: 3 ♂♂, Blue Mountains, E.W. Ferguson collection (one misidentified as Heterognathus geniculatus) (ANIC); 1 ♂, Macksville, 11.1990, leg. Wachtel (cPJ); 3 ♂♂, The Glade / Wonga Track, Dorrigo N.P., 13- 15.11.1990, red rotten wood, leg. T. Weir (ANIC); 1 ♂, Comboyne, leg. J. Armstrong (ANIC); 1 ♂, Orange, J. Armstrong (ANIC); 1 ♂, 4 ♀♀, misidentified as Scydmaenus princeps by H. Franz, Upper Williams River, 10.1926, leg. Lea & Wilson (SAMA); QUEENSLAND: 11 ♂♂, 4 ♀♀, Brisbane vic., 01.1991, leg. Wachtel (cPJ); 4 ♂♂, 2 ♀♀, Mount Superbus, 01.1995, leg. Wachtel (cPJ); 1 ♂, Mount Glorious, 12.1992, leg. Wachtel (cPJ); 1 ♂, 2 ♀♀, Brisbane, 03.1981, leg. Wachtel (cPJ); 2 ♂♂, Mount Tamborine, 12.1992, leg. Wachtel (cPJ); 1 ♂, Mt. Glorious, 21.12.1990, leaf & log litter with fungi, Berlesate, leg. J. Lawrence (ANIC); 1 ♂, Mount Glorious, 30 km WNW Brisbane, 03.09.1987, ex log of Ficus watkinsiana, leg. F.R. Wylie & M. DeBaar (ANIC); 6 ♂♂, Mount Glorious, 800 m, 28.06.1978, bark and log litter, leg. S. & J. Peck (ANIC); 5 ♂♂, Mount Glorious, 19- 21.12.1990, under bark and in rotten wood, leg. J. Lawrence (ANIC); ♂, Lamington NP, project IBISCA 700A, 29.10.2008, rain forest, bark spray, trees & logs, leg. F. Turco (ANIC); 2 ♂♂, Lamington N.P., (O’Reilly’s), 22- 27.10.1978, under bark and in rotten wood, leg. Lawrence & Weir (ANIC); 3 ♂♂, Lamington N.P., near O’Reilly’s, 25& 28.10.1993, leg. S.A. Ślipiński & J. Lawrence (ANIC); 2 ♂♂, Lamington N.P., Binna Burra, 900 m, 23.06.1978, rotten bark & litter, leg. S. & J. Peck (ANIC); 2 ♂♂, Lamington N.P., Binna Burra, 27.10.1993, under bark, in rotten wood and fungi, leg. S.A. Ślipiński & J. Lawrence (ANIC); 1 ♂, 1 ♀, Lamington N.P., Binna Burra, Old Cedar Roads, 11.08.2004, leg. M. Wanat (MNHW); 3 ♂♂, Manorina N.P., 500 m, 04.07.1978, under bark, leg. S. & J. Peck (ANIC); 4 ♂♂, Joalah N.P., Mount Tamborine, 500 m, rainforest, 22.06.1978, debris under bark, leg. S. & J. Peck (ANIC); 3 ♂♂, Joalah N.P., Mount Tamborine, 18- 21.10.1978, under bark of logs, leg. Lawrence & Weir (ANIC); 1 ♂, Dandabah, 2 km SE, 20.10.1991, on fungus on side of log, leg. T. Gush (ANIC); 3 ♂♂, Boombana N.P., 500 m, 04.06.1978, wet sclerophyll, under bark, leg. J. & S. Peck (ANIC); 2 ♂♂, McDonald N.P., Tamborine Mtn., 29.10.1993, leg. S.A. Ślipiński & J. Lawrence (ANIC); 2 ♂♂, Palm Grove N.P., Tamborine Mtn., 24 & 29.10.1993, under bark, in rotten wood and fungi, leg. S.A. Ślipiński & J. Lawrence (ANIC); 1 ♂, Cameron’s Scrub, site 3, 16.09.1998, 40 m, pyrethrum, trees, leg. Monteith & Bouchaard (QM); 1 ♂, Mount Superbus, 900 m, 8- 9.02.1990, pyrethrum, logs, leg. Monteith, Thompson, Janetzki (QM); 2 ♂♂, Tomewin Range, Upper Currumbin, 10.10.1989 and 19.10.1989, pyrethrum, trees & logs, leg. Monteith (QM); 1 ♂, Mount Chinghee, 720 m, 12 km SE Rathdowney, 17.12.1982, pyrethrum, rainforest, leg. Monteith, Yeates, Thompson (QM); 1 ♂, Boombana N.P., site 1, 07.11.2003, day hand collecting, rainforest, 440 m, leg. QM party (QM).
Revised diagnosis (based on males). Antennomeres 9 and 10 of subequal width, 9 only slightly shorter than 10 (Fig. 9); antennomere 9 bent at nearly right angle (Fig. 9); antennomere 10 with proximal asetose elevated region with triangular distal portion (Fig. 10); aedeagus in dorsal view (Figs 16, 18) with apical margin weakly rounded and as wide as about 1/3 of total width of median lobe, lateral subapical lobes broadly hook-shape, each slightly longer than broad and projecting strongly laterally and weakly distally, in lateral view (Figs 17, 19) distal region of median lobe weakly broadened, with dorsal margin broadly rounded; metaventrite (Fig. 70) with deep median impression about as broad as half width of metaventrite and filled with setae denser than those on lateral regions.
Redescription. Body of male (Fig. 15) slightly flattened, elongate and slender, BL 1.80–1.90 mm; pigmentation uniformly light to moderately dark brown, appendages indistinctly lighter (difference best visible in darkest specimens); cuticle moderately glossy, covered with vestiture of yellowish setae.
Head (Figs 7–8) in dorsal view transversely subrectangular, broadest at eyes, HL 0.33–0.35 mm, HW 0.33–0.38 mm; vertex and frons confluent and weakly convex, posterior margin of vertex distinctly concave, arcuate; tempora nearly as long as 2 × length of eye in dorsal view; supraantennal tubercles indistinct; frons over antennal fossae broadly subtrapezoidal and with straight anterior margin. Eyes small, nearly semicircular in shape, indistinctly emarginate posteriorly and oblique in relation to long axis of head. Punctures on frons and vertex fine, inconspicuous; setae short, sparse, suberect, those on tempora as sparse as those on head dorsum. Genae (Fig. 8) as sparsely setose as frons and vertex. Anterior (exposed) region of head capsule demarcated from neck region by narrow abrupt impression around occipital constriction, anterior margin of gular plate on neck region accentuated by minute rounded anteriorly-directed projection. Submentum (Fig. 8) lacking submental lobes, so that entire mentum is exposed; hypostomal ridges (Fig. 8) extending mesally and anteriorly to connect at middle, their median transverse portion distinct. Antennae (Figs 9–10, 15, 51, 58–59) long and slender, AnL 1.08–1.13 mm; three terminal antennomeres forming sharply delimited club; scape about 3 times as long as broad, distinctly broadening distally; pedicel twice as long as broad; antennomeres 3–4 each 1.5 × as long as broad, 5 twice as long as broad, 6 asymmetrical, 1.8 × as long as broad, 7 and 8 each distinctly transverse and strongly asymmetrical, 9 strongly asymmetrical, elongate and bent at nearly right angle, 10 indistinctly broader and slightly longer than 9, strongly asymmetrical, with proximal asetose expansion with triangular distal margin; 11 much shorter than 9 and 10 combined, nearly twice as long as broad, slightly asymmetrical.
Pronotum in dorsal view (Fig. 7) elongate, broadest near anterior third, PL 0.50–0.55 mm, PW 0.40–0.45 mm; anterior and lateral margins confluent and rounded; posterior corners obtuse-angled and blunt; posterior margin nearly straight; base with narrow but distinct posterior marginal carina and with two pairs of small, distinct, sharply marked and relatively deep antebasal pits, each slightly to distinctly transverse. Pronotal disc covered with fine and inconspicuous punctures; setae similar to those on frons and vertex, short, moderately dense, suberect. Ventrally (Fig. 8) prothorax with nearly asetose and impunctate hypomera; basisternal region sparsely covered with short recumbent setae, with indistinct vestiges of notosternal sutures at 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 (Fig. 15) oval, broadest slightly in front of middle, EL 0.95–1.03 mm, EW 0.65–0.70 mm, EI 1.39–1.54. Humeral calli weakly elevated; basal impression on each elytron barely marked; basal elytral foveae lacking; apices separately rounded. Punctures fine and inconspicuous; setae similar to those on pronotum. Hind wings not studied.
Metaventrite (Fig. 70) with large and deep longitudinal median impression about as broad as half width of ventrite, with diffuse lateral margins, filled with setae denser than those on surrounding areas, but subequal in lengths.
Legs (Figs 12–14, 15) long and slender; unmodified, except for distal penicillus on mesotibiae (Figs 13–14) and weakly broadened protarsomere 1 and ventral tenent setae distributed on protarsomeres 1–3 (Fig. 12); protarsi short, tarsomeres 1–4 each about 1.5 × as long as broad, tarsomere 5 3.5 × as long as broad and slightly shorter than tarsomeres 2–4 combined; mesotarsi long, tarsomere 1 nearly 5 × as long as broad and subequal in length to tarsomeres 2–4 combined, tarsomeres 2–4 each about 1.5 × as long as broad, tarsomere 5 nearly 3.5 × as long as broad, subequal in length to tarsomeres 3–4 combined; metatarsi as long as mesotarsi, tarsomere 1 about 3.5 × as long as broad, tarsomeres 2–4 each elongate but decreasing in length distally, tarsomere 5 3.5 × as long as broad, subequal in length to tarsomeres 3–4 combined.
Aedeagus (Figs 16–19) elongate but not very slender, AeL 0.35 mm, in dorsal view median lobe equally broad near proximal fourth and near distal fourth, with shallow and broad constriction; apical region subtrapezoidal, strongly tapering and with weakly rounded apical margin as wide as about 1/3 of total width of median lobe; lateral subapical lobes prominent and sharply demarcated from median lobe, each subtrapezoidal, slightly longer than wide, strongly projecting laterally and only slightly distally, each lobe with minute hook-like projection on proximal apical corner; ostium situated in subapical fourth of median lobe, flagellum with abruptly broadened and asymmetrical vesicular structure; median lobe in lateral view with slender distal portion delimited by deep submedian constriction, its dorsal surface relatively weakly rounded.
Female. Similar to male but with unmodified antennal clubs (Fig. 52), mesotibiae lacking distal penicilli, and metaventrite lacking impression; antennae on average slightly shorter in relation to body. BL 1.70–1.85 mm; HL 0.30–0.33 mm, HW 0.33–0.35 mm, AnL 0.95–1.05 mm; PL 0.48–0.53 mm, PW 0.40–0.43 mm; EL 0.93–1.00 mm, EW 0.65–0.68 mm, EI 1.41–1.48.
Distribution. CE Australia: SE Queensland (most commonly collected in vicinity of Brisbane) and eastern New South Wales.
Remarks. Among non-type specimens studied there is a male misidentified by Franz as S. princeps, and specimens misidentified by earlier authors as S. geniculatus.
Males of Scydmaenus beechmonti are easy to identify by the unique antennal modification. Only the newly described S. curviclavatus sp. n. has similar antennae. However, in S. beechmonti, the antennomere 9 is strongly bent at a nearly right angle (Fig. 58), whereas in S. curviclavatus sp. n. this antennomere is only weakly curved (Fig. 66). The aedeagi of these species clearly differ. That of S. beechmonti in dorsal view (Fig. 16) is equally broad in sub-basal and subapical regions, whereas the aedeagus of S. curviclavatus sp. n. (Fig. 42) is strongly broadening distally, so that the subapical region is much broader than the basal portion. Moreover, the shape of the subapical lateral lobes of the median lobe is different: hook-shaped in S. beechmonti vs. rounded subtriangular in S. curviclavatus sp. n.
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 11-15, DOI: 10.11646/zootaxa.5371.1.1, http://zenodo.org/record/10144644