Brachypeplus planus Erichson, 1842

Kirejtshuk, Alexander G. & Kovalev, Alexey V., 2022, Monograph on the Cillaeinae (Coleoptera: Nitidulidae) from the Australian Region with comments on the taxonomy of the subfamily, Zootaxa 5103 (1), pp. 1-133 : 69-73

25. Brachypeplus planus Erichson, 1842

Figs 19 , A–H

Brachypeplus planus Erichson, 1842: 149 : TAS, Van Diemen's Land;

= Brachypeplus (Tasmus) planus: Murray, 1864: 292 ;

?= Brachypeplus (Tasmus) castaneipes: Murray, 1864: 293 ; Melbourne.

Specimens examined. Type specimens: lectotype of Brachypeplus planus , male ( ZMB), here designated and 1 paralectotype female ( ZMB)—“ planus Er., Van Diem., Schager ”, “8335.” Other specimens: Australia, WA: 27 exx ( ANIC, ZIN)— “ Margaret River, WA (35.57 S 115.04 E), 3 km SE, 15.XI.69, under bark of recently falled tree, E.B. Britton ”; 1 ex ( ANIC)— “ 5 miles NW of Augusta, WA, 4 April 1968, J.F.B. Common & M.S. Upton ”; 1 ex ( ANIC)— “ 15 miles WSW of Collic, WA, 6 April 1968, J.F.B. Common & M.S. Upton ”; 1 ex ( ANIC)— “ 16 miles WSW of Collic, WA, 7 April 1968, J.F.B. Common & M.S. Upton ”; 4 exx ( TMB)— “Austral. Occid. 1192”; 1 ex ( TMB)— “ Western Australia, Perth, Penbenton , 10.VII.1968, N PER–R.3, Dr. J. Loksa ”; NSW: 1 ex ( ANIC)— “ Tantawangalo Mt. , Bombala District , 24.II.34, C.F. Hill ”; 3 exx ( SAM)— “Dividing Rg., V. Blackb’s Coll. ”; 14 exx ( SAM)— “ Galston , NSW, Lea & Pumpbell”; 3 exx ( SAM)— “ Forest Reefs , NSW, Lea ”; 1 ex ( ANIC)— “ 4 mi W of Woodburn, NSW, 3.XI.65, M.S. Upton ”; 5 exx ( ANIC, ZIN)— “ Wiangaree S.F., NSW, Isaksson Ridge , 1050 m, 29 Feb.—3 Mar. 1980, A. Newton, M Thayer”, “ window trap 592”; 2 exx ( ANIC, ZIN)— “ Mt. Kosciusko , NSW, Summit Rd. , 4230, 12.XII.66, T.G. Wood ”; 1 ex ( ANIC)— “ New England Nat. Park , NSW, 12.X.66, E. Britton ”; 1 ex ( ANIC)— “ Kangaroo Valley , 21 August 1988, Richard Bejsak”, “ Brown Mt. , NSW, 19.X.72, R.J. Kohout ”; 4 exx ( CMS) –“NSW, Upper Kangaroo Valley , 21 August 1988, Richard Bejsak”; 1 ex ( CMS) – “NSW, Vattai, 29.7.1982, Richard Bejsak”; 1 ex ( ANIC)— “Canberra, ACT, 1.II.29, G.F. Hills ”; ACT: 1 ex ( ANIC)— “ Black Mt. , ACT, light trap, 23.XI.65, M. Upton ”; 1 ex ( ANIC)— “ 35.25S 148.46E, 1 km N of Mt. Franklin, 1280 m, ACT, 16 Oct. 1979, Lawrence & Weir”; SA: 2 exx ( ANIC)— “Maryvale ( SA), 2–5–1969, B. May ”, “ C.G.L. Goodling Collection donated to ANIC 1979”; VIC: 1 ex ( ANIC)— “ Upper Tarago R., Vict., 6.4.1969, G. May ”, “ C.G.L. Goodling Collection donasted to ANIC 1979”; 1 ex ( SAM)— “ Victoria, Blackburn”; 1 ex ( TMB)— “ Australia, Victoria, Melbourne”; 2 exx ( CMS)— “ Victoria, Melbourne”; 5 exx ( TMB, ZIN)— “ Stevensens Falls , Marysville, 25.VII.1968, N MEB-R.3, Dr. J. Loksa ”; 6 exx ( SAM)— “Victorian Alps, Blackburn”; 2 exx— “Gippsland”; 1 ex ( SAM)— “Monbulk, Vic., 24.4.02, Jarvis”; 2 exx ( ANIC)— “Vict., 12 km E Warburton, 215 m, 12–16.I.1980, Eucalyptus forest , A. Newton, M. Thayer ”, “fibrous bark of Eucalyptus log, fermented stage”; 1 ex ( ANIC)— “Vict., Warburton , Cement Creek , 670 m, 10–17.I.1980, Notogagus cunninghamii etc., A. Newton, M. Thayer ”; TAS: 8 exx ( ANIC, ZIN)—“ 42.41S 146.43E, Mt. Field N.P., 160–240 m, Tas, 30 Jan. 1980, Lawrence & Weir”; 1 ex ( ANIC)— “Tas, Mt. Field N.P., SE end Lake Fenton , 1 000 m, 30 Jan.—5 Feb.80, A. Newton, M. Thayer ”, “dusk flight”; 1 ex ( ANIC)— “Tas, Mt. Field N.P., Lady Barron Falls Tr., c.170 v., 2.II.1980, A. Newton, M. Thayer ”, “under bark, rotten log”; 1 ex ( ANIC)— “Tas., Lyell Hwy at Franklin R., 55 km ESE, Queenstown, 400 m, 19–20.II.1980, A. Newton, M. Thayer, Notofagus cunninghamii, etc. forest”, “ window trap, 587”; 1 ex ( ANIC)— “Tas., 4.4 km SE Weldborough, 460 v, 12–14 Feb. 1980, Notho. Euc. forest , A. Newton, M. Thayer ”; 6 exx ( ANIC, ZIN)— “ 42.38S 146.26E, 7 km WNW of Mt. Field West, 460 m, Tas., 1 Feb.1980, Lawrence & Weir”; 10 exx ( AMS)— “Launceston, Mt ., Lampty R.”; 3 exx ( SAM)— “Launceston”; 4 exx ( SAM)—“ Tasmania, A. Simpson ”; 4 exx ( SAM)— “ Tasmania, Blackbs Coll.”; 1 ex ( TMB)— “Tas., Bruny Island , 25.I.1984, G.F. Bornemissza ”; 1 ex ( TMB)— “E Tas. Elephant Pass, G.F. Bornemissza ”; 3 exx ( SAM)— “ Brunni J. Tas: Lea” 4 exx ( SAM)— “Zeeham”; 1 ex ( SAM)— “ Mole Creek ”; 1 ex ( SAM)— “from Fomes hemitephrus, Tas: L. Rodway ”; 2 exx ( ANIC)— “Tas., The Cap, Florentine Rd, 15 km WNW, Maydena, 600 m, 1 Feb.1980, Nothofagus etc., A. Newton, M. Thayer ”, “under bark Nothofagus cunninghamii”; 1 ex ( ANIC)— “ 42.02S 146.33E, 12 km NNE TAS. Bronte Park, 20 Jan. 1983, J.C. Candale ”; 1 ex ( ZNIC)— “ 42.43S 146.29E, 2 km ENE of Tim Shea, 600 m, Tas., 1 Feb.1980, Lawrence & Weir”; 1 ex ( ANIC) – “ 42.41S 146.43E, Mt. Field NP, 160–240 m, Tas., 30 Jan. 1980, Lawrence & Weir”, “flying at dusk.”

Diagnosis. This species can be easily diagnosed after the above key to Australian and Tasmanian species of the genus. Brachypeplus planus is distinct among Australian species due to its comparatively large, subunicolorous dark brown to blackish and pubescent body (only articulation of abdominal segments can be somewhat lighter). Besides, this species is characterized by the very long antennomere 3 (about 2.5 × as long as antenomere 2), very coarse and dense punctation on the head and below thoracic sclerites, comparatively wide pregenal processes with rounded outer apical angle, metatibiae gradually narrowing from middle towards apex. The characteristic structure of metatibia in Brachypeplus planus is rather similar to that in B. wattsensis , although these species are different in many other characters (body coloration and sculpture of integument, size of eyes, outline of temples, length of antennae, pronotal shape, shape of scutellar shield and exposed laterosternites—see also the below notes to the lastmentioned species).

Note on synonymy. The type series of Brachypeplus castaneipes are missing in the arranged part of the collection of NHML but the describer wrote that it, in contrast to B. planus , is “smaller, and apparently narrower, although, perhaps, the proportions are the same. In every detail it tallies very closely with that species, except, perhaps, that the sides of the thorax are straighter and less rounded-in in front. The inflexed edges of the elytra and the under side of the thorax are ferrugineo-piceous, and the antennae and legs are still lighter, instead of being dark piceous as in B. planus .” Thus, it seems to be reasonable to preliminarily regard this name as a junior synonym of Brachypeplus planus and, if any true type specimen is not found among not yet arranged materials of Murray in NHML, it would be reasonable to choose any not mature adult of the Brachypeplus planus in NHML to designate a neotype of B. castaneipes .

Addition to description. Body length 3.6–6.7 mm. Body dark brown to blackish, with somewhat lighter intersegmental articulations of abdomen and appendages; upper surface with short and moderately conspicuous brownish to reddish pubescence, pronotal and elytral sides with moderately long cilia.

Head with very coarse punctures (more than 2.0 × as coarse as eye facets), interspaces between punctures very small (about 0.3 of puncture diameter), obliterated to smooth. Pronotum with punctures somewhat coarser than eye facets (but markedly finer than those on head), interspaces between punctures subequal or greater than one puncture diameter, obliterately alutaceous to smooth. Elytra with longitudinal rows of punctures about as coarse as those on head located in bottom of very shallow striae, interstrial spaces with one row of finer punctures, to apices punctation becoming less regular, interspaces between punctures with obliterated microreticulation. Below thoracic sclerites and abdominal ventrite 1 with very coarse punctures (nearly as coarse as those on head), interspaces between them densely microreticulate.

Antenna somewhat longer than head wide, with scape nearly as long as antennomere 3, less than 2.0 × as long as wide, pedicel about 0.4 × as long as antennomere 3, antennal club somewhat less than 0.2 of total antennal length, elongate oval and about 1.6 × as long as wide. Pregenal processes rather wide and with rounded outer apical angle. Mentum with slightly projecting anterior angles, almost 5.0 × as wide as long. Pronotum widest at middle, with clearly trapezoid-like excised anterior edge, projecting anterior angles and nearly clear tip, moderately subexplanate sides (less widely subexplanate than scape wide), clearly and finely serrate lateral edge and clearly bi-emarginate base. Scutellar shield subpentagonal and with subangular to subtruncate apex. Elytra with sides somewhat less widely explanate than those of pronotum. Abdominal laterosternites V slightly more 2.0 × as long as wide at apex, laterosternites VI more than 2.5 × as long as wide at apex. Female pygidium slightly transverse, about 1.4 × as long as tergite VI and truncate at apex.

Prosternal process nearly 4.0 × as wide as distance between procoxae and widely rounded at apex. Distance between mesocoxae somewhat less than 2.0 × greater and that between metacoxae slightly greater than that between procoxae. Abdominal ventrite 3 about as long as ventrites 1, ventrite 2 about 0.7 × as long as each of ventrites 1 and 3, ventrite 4 longest among ventrites 1-4. Male pygidium slightly transverse, 1.2–1.3 × as long as tergite VI and usually emarginate at apex, with rounded apical lateral angles. Male hypopygidium more than 1.7 × as long as ventrite 1 (about 1.4 × as long as long ventrite 4). Female hypopygidium about 2.0 × as long as ventrite 1 (less than 1.5 × as long as long ventrite 4).

Pro- and mesotibiae subtriangular, somewhat narrower than antennal club, with outer apical angle not projecting. Metatibia subparallel-sided in distal 0.8 and gradually narrowing before apex. Tibial spurs short and thin. Male protarsus about 0.5 × as wide as protibia, female protarsus as well as meso- and metatarsi of both sexes narrower.

Male anal sclerite not completely dorsoventrally compressed and with widely rounded to subtrruncate and finely serrate posterior edge. Aedeagus heavily sclerotized. Tegmen 2.5–3.0 × as long as wide and narrowed at rounded apex. Penis trunk slight shorter than tegmen, 2.5–3.0 × as long as wide, narrowed at distal 0.3 to sharply acuminate apex. Armature of inner sac of penis represented by diffuse small sclerotized granules concentrated in unclear formations and three pairs of sclerites at its end: one pair of long sclerites approached to each other and two pairs at sides of latter (one at middle and another at proximal end). Ovipositor slightly to moderately sclerotized and rather narrow; gonocoxites comprising almost 0.5 of total length of ovipositor, their lateral lobes usually with very slight sclerotization and about 0.3 × as long as gonocoxites in general, outer outline of gonocoxites clearly concave at distal half and subparallel-sided to apex; rather wide apex with rather long styli located subapically.

Distribution. Australia: WA, QLD, NSW, ACT, SA, VIC, TAS (type locality: Van Diemen's Land).

Notes on bionomy. This species has collected in places quite characteristic of many other members of the genus, particularly under bark of trees and different decaying products of plant origin.

Figures

FIGURE 19. Brachypeplus planus, orig. A, B, C: male from TAS (“…Mt. Field West…”); A: body, dorsal; B: shoulder part of elytron, dorsal; C: head and thorax, ventral; D-G: male from Tasmania (“…Mt. Field N. P…”); D: male anal sclerite and spiculum gastrale, ventral; E: tegmen, ventral; F: penis trunk, dorsal; G: proximal part of inner sac with armature; H: female from Tasmania (“…Lower Bardon R…”); ovipositor, ventral. Scale bars: a = 1.0 mm to Fig. A; b = 1.0 mm to Fig. B; с = 0.5 mm to Fig. C; d = 0.25 mm to Figs D–H.