Osoriellus brevicornis ( NOTMAN, 1920 ) Irmler, 2014

Irmler, Ulrich, 2014, The Neotropical species of the genus Osoriellus FAGEL, 1959 (Coleoptera: Staphylinidae: Osoriinae), Beiträge Zur Entomologie = Contributions to Entomology 64 (2), pp. 231-354 : 261

Osoriellus brevicornis ( NOTMAN, 1920) new combination ( Figs 53A , 96F )

Osorius brevicornis NOTMAN, 1920: 698

Type material examined: U.S.A.: Florida, Pensacola , female, 11.4.1914 (holotype in ANHM) .

Diagnosis: The species resembles O. rugipennis concerning the overall shape of the pronotum and the microsculpture, but microsculpture is weaker than in O. rugipennis and the colouration is yellow and not dark brown. The most conspicuous character of O. brevicornis are the short antennae with the wide third and fourth antennomeres and, in particular, the short, transverse antennomeres five and six. Moreover, the following antennomeres are distinctly thicker forming an indistinct club. According to NOTMAN (1920) the species occurred in southern U.S.A. and in northern Mexico, Colima, E. Chihuahua (106°04.13W, 28°29.30N), leg. Conradt. This place is located at the periphery of Chihuahua city which is in northern Mexico and part of the Nearctic region. As it was not found in southern Mexico, the species is assumingly not part of the Neotropical fauna.

Description: Length: 4.0 mm. Colouration: Head and abdomen brown, pronotum and elytra light red, legs and antennae yellow.

Head: 0.60 mm long, 0.80 mm wide; eyes large, but not prominent, as long as temples; disc with dense setiferous punctures except on wide midline and smaller spot at base of antennae; on average, interstices between punctures half as wide as diameter of punctures; surface with distinct netlike microsculpture, slightly shiny.

Antennae short, second antennomere oblong, longer than wide; third antennomere conical and distinctly shorter than second; fourth antennomere conical and still shorter than third; fifth and sixth antennomeres much wider than long, but distinctly smaller than following antennomeres; antennomeres seven to eleven much wider than preceding antennomeres; forming indistinct club.

Pronotum: 0.80 mm long, 0.85 mm wide; widest at anterior edge; evenly convergent in smooth curve to posterior angles; posterior edge two-third as wide as anterior edge, lateral and posterior margin fine; anterior edge not margined; with dense setiferous punctures, setae pointing to wide impunctate midline; on average, interstices between oblong punctures as long as longitudinal diameter of punctures; surface with netlike microsculpture; microsculpture slightly weaker than on head.

Elytra: 0.90 mm long, 0.90 mm wide; with deep coriaceous ground-sculpture and irregular rows of setiferous punctures, setae pointing to middle.

Abdomen with setiferous punctation dense and deep; setae pointing to middle.

Protibia: 0.43 mm long, 0.15 mm wide; with 8 spines at outer edge; apical 3 spines inserted on short digits; WLR: 1.75; anterior face with a row of 5 setiferous punctures; posterior face densely covered by long yellow setae.

Aedeagus unknown.

Figures

Fig. 53-57: Osoriellus-s. str.-group: Osoriellus brevicornis (53), O. micros (54), O. surinamensis (55), O. grossopunctatus (55); Osoriellus ashei (57); antenna (A), protibia (B), aedeagus in lateral aspect (C); scale bar: 0.1 mm.

Fig. 96: Osoriellus-s. str.-group: Head, pronotum and elytra of O. surinamensis (A), O. salvini (B), O. obtusicollis (C), O. levyi (D), O. loksai (E), O. brevicornis (F); scale bar: 0.5 mm.