Gymnocychramus bicolor, Lawrence & Kirejtshuk, 2019

Lawrence, John F. & Kirejtshuk, Alexander G., 2019, Review of the Australian Cyllodini (Coleoptera: Nitidulidae: Nitidulinae), with descriptions of new taxa, and notes on the genus Macleayania (Nitidulini), Zootaxa 4544 (3), pp. 301-334 : 325-326

Gymnocychramus bicolor sp. nov.

( Figs 12, 23 , 32–34 , 46 , 60–61 )

Diagnosis. This species differs from G. politus in its smaller size, primarily reddish-orange colour, more densely packed elytral macropunctures, weakly convex prosternum and absence of large, elongate-oval pits on the ventral surface.

Description. Length = 3.00–5.00 (3.98 ± 0.50, n = 12) mm. Body ovate, slightly convex: body length/elytral width = 1.36–1.46 (1.42); greatest depth/elytral width = 0.59–0.67 (0.62). Head, pronotum, scutellar shield, pygidium, undersurfaces and legs reddish-orange; elytra black. Dorsal vestiture very short and not visible under lower magnifications. Head 0.85× as long as wide. Eyes 0.27× head width. Temples 0.66× as long as eye, distinctly curved. Frontoclypeal suture represented by a transverse shallow depression. Clypeus 0.43× as long as wide at base, sides subparallel to weakly concave apex. Labrum about 0.30× as long as wide. Antennal scape 1.25× as long as wide and 1.50× as long as pedicel; antennomere 3 about 1.25× as long as 4; club 0.75× as long as antennomeres 3–8 combined and 1.50× as long as wide; terminal antennomere 0.90× as long as wide. Mandible strongly, gradually curved towards unidentate apex; incisor edge densely lined with spines; mola well-developed with numerous transverse ridges; narrow membrane of prostheca becoming broader and setose apically. Apical maxillary palpomere 2.0× as long as wide, widest at base, with narrowly rounded apex. Mentum 0.5× as long as wide, widest at base; apex biemarginate on either side of short, rounded lobe and between paired anterolateral rounded lobes. Apical labial palpomere about 1.67× as long as wide, widest near base, with broadly rounded apex. Genal ridges slightly sinuate, but almost straight, extending to ends of temples; subocular ridges absent. Pronotum 0.36–0.46 (0.42)× as long as wide, widest at base, lateral margins visible for their entire lengths from above; anterior edge weakly emarginate, forming slightly produced and subangulate anterior angles; posterior angles more or less right; posterior edge evenly curved, with distinct marginal bead, obscured at middle; disc slightly, evenly convex; punctation fine and sparse, punctures usually separated by one to two diameters; interspaces finely sculptured, with irregular, curved ridges, producing dull sheen. Prosternum 0.65× as long as mid length of procoxal cavity, slightly convex, with large, obliquely oval pubescent patch at middle in male; prosternal process 0.40× as wide as mid length of procoxal cavity, not or only slightly curved behind coxae, with angulate apex and distinct vertical wall. Scutellar shield 0.28× as wide as pronotum, with subacute apex slightly rounded at tip. Elytra 0.97–1.06 (1.03)× as long as wide and 2.20–3.03 (2.59)× as long as pronotum; lateral margins moderately broad and visible for their entire lengths from above; elytral apices more or less truncate, exposing most of pygidium; humeri weakly developed; disc with nine more or less regular rows of larger punctures, densely placed within rows, with scattered smaller punctures in between, some of them forming less regular rows; epipleura slightly oblique and partly visible in lateral view, broad at base, gradually narrowing apically and extending to posterior edge of ventrite 4. Anterior edge of mesoventrite on almost the same plane as metaventrite, without posternal rest or median carina, slightly raised posteriorly, its posterior edge emarginate. Mesocoxae separated by 0.40× longest longitudinal diameter of mesocoxal cavity. Metaventrite strongly convex, distance between meso- and metacoxal cavities 0.31× greatest width of ventrite; discrimen extending almost to base of anterior process; postcoxal lines beginning at about mesal third of each coxal cavity, adjacent to edge of coxal cavity until about middle, then gradually curving posteriorly and extending to about middle of lateral edge of ventrite, forming relatively small axillary spaces and lined with series of very small oval pits; posterior edges of mesocoxal cavities not joined by fine line. Metanepisternum 3.58× as long as wide, widest near anterior end and narrowed posteriorly. Metacoxae separated by 0.82× mid length (shortest diameter) of metacoxa. Protibia distinctly expanded apically, its outer edge lined with short serrations, each of which is associated with a short, blunt spine; outer apex with fixed tooth. Mesotibia moderately expanded and apically subacute, its outer edge lined with long spines, the longest in a cluster at the outer apical angle and several more along apical edge; metatibia slightly expanded, its anterior edge lined with spines. Anterior faces of meso- and metatibiae each with longitudinally oblique setal row. All basal tarsomeres expanded and lobed. Abdominal ventrite 1 at lateral third 0.80× as ventrite 2, with intercoxal process broadly rounded and postcoxal lines shallowly curved and not extending to middle of ventrite; ventrites 2–4 subequal in length, each with a fine transverse carina near anterior end and another near posterior end; ventrite 5 1.73× as long as 4, with a fine transverse carina near base and broadly rounded at apex. Pygidium in both sexes with straight basal carina and broadly rounded apex. Tergite VIII (anal sclerite) in male apically rounded. Tegmen ( Fig. 32 ) 2.0× as long as wide, not strongly curved at apex; sides subparallel; apex with two broadly rounded lobes separated by deep cleft, side of each lobe bearing three ventral setal tufts; anterior strut 0.50× as long as body of tegmen with expanded, rounded apex. Penis ( Figs 33–34 ) subequal in length to body of tegmen and 3.0× as long as wide; sides subparallel for basal two-thirds, then converging to form a short dorsal lobe, broad at base and acute at apex, and a much longer ventral lobe broad at base and narrowing to acute apex; anterior penile strut 1.2× as long as body of penis. Ovipositor ( Fig. 46 ) 2.37× as long as wide, widest at base, flattened; paraprocts 0.80× as long as gonocoxites, which are 1.65× as long as their combined widths, widest at base and gradually narrowing to subacute, contiguous apices, without gonostyli.

Type specimen: Holotype, ♂: “ Dorrigo Nat. Park , NSW, on fungus, 24.i.67, N. Fenton ” (ANIC type #25- 014996).

Paratypes. NSW: Booyong (28.45S, 153.27E), xi.1904, Helms Colln (4, ANIC, BMH) ; Dorrigo, W. Heron (2, SAM, ZIN) ; Dorrigo Nat. Park , 24.i.1967, on fungus, N. Fenton (5, ANIC, ZIN) ; Minnamurra Falls , 16.ii.1958, on Clathrus cibarius, C. E. Chadwick (33, ACSU, ANIC, QMB) ; Waiangaree St. For. (28.22S, 153.05E), 1050m, 10–12.ii.1983, T. Weir, A. Calder (1, ANIC) ; QLD: Bald Mtn area, 3–4000’, via Emu Vale , 27–31.i.1972, G. B. Monteith (2, QMB) ; Bally Knob Summit (17°39’S, 145°30’E), 1100m, open forest, 6.xii.1998 – 6.ii.1999, 2148, intercept, Monteith & Cook (1, QMB) ; Innisfail, G. L. Froggatt (5, ANIC, QMB, ZIN) ; Julatten , 24.iii.1992, stinkhorn, B. P. Moore (1, ANIC) ; Kuranda , Griffith Collection (1, SAM) ; Mt. Glorious , 630m, 14.xi.1986 – 30.i.1987, flight intercept trough trap, T. Hiller (2, ANIC, ZIN) ; National Park , i.1928, H. J. Carter (2, ANIC) ; National Park , xi.1930, H. Hacker (2, QMB) ; North Queensland, H. Peters (1, ANIC) ; Palm Island , M. J. Mackerras (1, ZIN) ; Shipton’s Flat , 1981, Lewis, Roberts (1, ZIN) ; Tamborine Mt. 16.ii.1966, E. M. Exley (8, ANIC, QMB, ZIN) ; Wallaville, T. L. Bancroft (1, ANIC) ; Windsor Tableland , 28.ii–6.iii.1992, flight intercept trap, J. Hasenpusch ( QDPC) .

Distribution. Northern NSW to northern QLD.

Biology. A series of adults were collected on the fruiting body of Ileodictyon cibarium Tul. (as Clathrus cibarius ) ( Phallales : Clathraceae ) ( Coetzee 2010). One specimen was also collected from an unidentified “stinkhorn”.

Etymology. From the Latin bis, two and color, coloris, hue, tint.

Figures

FIGURES 12–23. Habitus: 12, Gymnocychramus bicolor sp. nov. (4.0 mm), dorsal; 13, Pallodes beccarii Grouvelle (3.0 mm), dorsal; 14, same, ventral; 15, Pallodes nigroapicalis sp. nov. (2.8 mm), dorsal; 16, same, lateral; 17, same, posterodorsal; P. beccarii, dorsal, teneral (2.5 mm); 19, P. beccarii, ventrolateral; 20, Macleayania vesca (Olliff) (3.3 mm), dorsal; 21, M. amphotiformis (Reitter) (4.2 mm), dorsal; 22, same, ventral; 23, G. bicolor, lateral. Fig. 20 from Lawrence & Ślipiński (2013). All figures © CSIRO, Australia.

FIGURES 24–42. Tegmina, ventral and penises, dorsal, with tegminal strut and penile strut deleted: 24–25, Camptodes aff. humeralis (Brullé): 24, tegmen; 25, penis; 26–27, Coxollodes loriai (Grouvelle): 26, tegmen; 27, penis; 28–29, Cyllodes ruficeps (Reitter): 28, tegmen; 29, penis; 30–31, Cyllopallodes limbatus (Reitter): 30, tegmen; 31, penis; 32–34, Gymnocychramus bicolor sp. nov.: 32, tegmen; 33, penis; 34, endophallus; 35–36, Gymnocychramus politus Lea: 35, tegmen; 36 penis, showing endophallus; 37–38, Macleayania amphotiformis (Reitter): 37, tegmen; 38, penis; 39–40, Pallodes beccarii Grouvelle: 39, tegmen; 40, penis; 41–42, Pallodes nigroapicalis sp. nov.: 41, tegmen; 42, penis. All figures © Zoological Institute, Russian Academy of Sciences, St. Petersburg.

FIGURES 43–49. Ovipositors, ventral: 43, Coxollodes loriai (Grouvelle); 44, Cyllodes ruficeps (Reitter); 45, Cyllopallodes limbatus (Reitter); 46. Gymnocychramus bicolor sp. nov.; 47, Gymnocychramus politus Lea; 48, Pallodes beccarii Grouvelle; 49, Pallodes nigroapicalis sp. nov.

FIGURES 59–69. Genitalia: 59, Camptodes aff. humeralis (Brullé), apex of Ovipositor, ventral; 60–61, Gymnocychramus bicolor sp. nov., apex of penis: 60, dorsal (arrow pointing to apex of dorsal lobe); 61, same, lateral; 62–63, Gymnocychramus politus Lea, apex of penis: 62, dorsal; 63, lateral; 64–67, Macleayania vesca (Olliff): 64, apex of tegmen, dorsal; 65, base of tegmen, dorsal; 66, apex of penis; 67, apex of penile strut; 68–69, Macleayania amphotiformis (Reitter): 68, base of tegmen; 69, apex of penile strut. All figures © CSIRO, Australia.