Glyptoma opacum ( SHARP, 1876 )

Irmler, Ulrich, 2015, The neotropical genus Glyptoma ERICHSON, 1839 with descriptions of new species and a key to the species (Coleoptera: Staphylinidae: Osoriinae), Beiträge Zur Entomologie = Contributions to Entomology 65 (2), pp. 297-325 : 302-303

Glyptoma opacum ( SHARP, 1876)

( Figs 3A, B, C , 20D )

Thoracophorus opacus SHARP, 1876: 418

Calocerus zischkai SCHEERPELTZ, 1970: 132 new synonymy

Type material examined: Holotype: female, Brazil: Est. Amazonas, Tefé (64°41'W, 3°21'S) ( BMNH) ; Syntypes of Glyptoma zischkai : 1 male, 1 female, Bolivia: Region Chaparé , 400 m elev., 14.08.19954, leg. R. Zischka ( NHMW) .

Further material: Panama: 1 male, 3 females, Old Plantation Rd. , 6.9 km S. Gamboa (79°40'W, 9°05'N), 80 m elev., beating vegetation, 27.5.1995, leg. J. Jolly & C. Chaboo ( KNHM, UIC) ; Brazil: male, Amazonas, Téfé without further data (det. as Thoracophorus humerosus FAUVEL ) ( BMNH) ; Est. Pará , 2 females, Caratatéua; Ilha de Oteiro (48°25'W, 1°14'S), 15.05.1974, leg. R. T. Schuh ( AMNH) ; 1 male, Jacaréacanga (57°38'W, 6°16'S), 15.12.1969, leg. R. Barbosa ( AMNH) ; female, Pará , without further data ( BMNH) ; French Guyana: 1 male, Roura (52°19'W, 4°43'N), 08.01.1999, leg. P. Krásensky ( UIC) ; 2 males, without further data, leg. Charvein ( BMNH) ; Surinam: 1 female, Commewijne, Akintosela, 39 km SE Suriname River bridge road to Refi Doiti (54°55.15'W, 5°16.17'N), under bark, 40 m elev., 02.07.1999, leg. Z. Falin, ( KNHM) ; Peru: 1 male, Pucallpa, 60 km W., Estacion IVITA (74°80.5'W, 8°46.4'S), primary forest, 22.06.1988, leg. A.A. Zakharov ( UIC) ; Bolivia: Region Chaparé (~ 64°44'W, 14°05'S), 400 m elev., 14.7.1954, leg. R. Zischka ( NHMW) .

Diagnosis: G. opacum is characterised by the large size and the totally matt surface. In contrast to G. simile , the clypeus is also covered by a dense and deep microsculpture. SCHEERPELTZ (1970) distinguished G. zischkai from G. opacum by the larger size of the first species. However, in contrast to SCHEERPELTZ’s measures the type specimen of G. zischkai is only 4.0 mm long and not 4.5 to 5.0 mm as published by SCHEERPELTZ (1970). I found no difference between the type specimens of G. zischkai and G. opacum . The aedeagus of the G. zischkai type also shows no difference to the other male specimens identified as G. opacum ( SHARP, 1876) .

Description: Length: 4.0 mm. Colouration: Black; antennae dark brown; legs slightly lighter brown.

Head: 0.48 mm long, 0.66 mm wide; eyes large; slightly prominent and as long as temples; shape of temples cheek-like; post-ocular part shortly parallel, then abruptly curved and narrowed to neck; sides of head in front of eyes parallel up to base of antennae; parallel part longer than eyes; then abruptly narrowed in sinuate curve to front margin; punctures large and dense; interstices between punctures less than one fourth as wide as diameter of punctures; surface of vertex including surface of punctures covered by dense isodiametric narrow microsculpture; surface of vertex totally matt; clypeus more sparsely punctate, but surface as matt as on vertex.

Antennae slightly shorter than head, pronotum and elytra combined; first antennomere approximately rectangular and thick; distinctly thicker and longer than short second antennomere; second antennomere one fifth narrower than first and shorter than half of length of first; following antennomeres wider; fourth antennomere as wide as first, but still wider than long; antennomeres five to ten approximately quadrate or slightly longer than wide; all antennomeres with dense setation; setae only half as long as width of antennomeres.

Pronotum: 0.61 mm long, 0.66 mm wide; approximately parallel in anterior half, in posterior half emarginate and narrowed to rounded obtuse posterior angles; sides in anterior half undulate; front margin sinuate near apical angles, thus, anterior margin slightly prominent in middle; punctation as dense and deep as on head; midline indistinctly depressed in anterior half; in posterior half with indistinct transverse impression; surface with similar dense microsculpture as head; matt.

Elytra: 0.87 mm long, 0.87 mm wide; sides slightly curved; widest in middle; shoulders smoothly curved, but shortly denticulate; inner carina distinct; lateral carina absent or indistinctly restricted shortly behind shoulders; punctures large and dense; much larger than on head and pronotum; interstices between punctures indistinct and irregular; restricted to only narrow carinae; between large punctures minute setiferous punctures; total surface including carina with same dense isodiametric microsculpture as head and pronotum; surface totally matt.

Aedeagus with narrow apical lobe; apical lobe distinctly longer than basal lobe and smoothly curved; acute apex shortly pointing ventrally; without sensillae; narrow paramere short; only half as long as apical lobe; straight with short acute apex; at base with two sensillae.

Figures

Figs 20: Fore body of Glyptoma laeviceps (A), G. cicatricosa (B), G. rossii (C), G. opacum (D), G. simile (E); scale bar 0.5 mm.

Figs 2–6: Aedeagus (A), antenna (B) and microsculpture of head (C) of Glyptoma laeviceps (2), G. opacum (3), G. cicatricosa (4), G. rossii (5), G. simile (6); scale bar: 0.1 mm.