Osoriellus indescriptus, 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: 272-273

publication ID

http://doi.org/ 10.21248/contrib.entomol.64.2.231-354

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scientific name

Osoriellus indescriptus

n. sp.

Osoriellus indescriptus   n. sp.

( Figs 44 View Fig A-C, 94B)

Type material: Holotype, male: USA, Bahamas: South Bimini Island , 1.4.1952, leg. E. Mayr ( AMNH).  

Paratypes: USA, Bahamas: 30 specimens   with same data as holotype   ; 99 specimens, 1.5.1951, leg. C. Crazier; 17 specimens 1.6.1951, leg. C. Crazier; 5 specimens, 1.7.1951, leg. P. Vaurio; 11 specimens, 1.8.1951, leg. P. Vaurio ( ANHM, UIC)   ; Andros Island, Middenhair Coppice , 2.1 mi S, 0.7 mi E Staniard Creek, low interior coppice litter   , 1 specimen, 6.05.1994, R. Anderson ( AMNH); Church’s Blue Hole , 1.7 mi E Love Hill, high interior coppice litter   , 4 specimens, 26.04.1994, leg. R. Anderson ( KNHM)   ; London Ridge , 2.7 mi N, 0.8 mi E Forfar F. Stn., high interior coppice litter   , 1 specimen, 06.05.1994, leg. R. Anderson ( KNHM).

Diagnosis: The species is closely related to O. exiguus   . Both species cannot be shurely identified without dissection of the aedeagus. On average, O. indescriptus   is more slender and slightly darker than O. exiguus   and the punctation of the pronotum is slightly deeper and denser. However, the species can be easily separated by the shape of the aedeagus. The apical lobe of O. exiguus   is slender and smoothly curved, whereas it is thick and triangular in O. indescriptus   .

Description: Length: 2.5 mm long. Colouration: Light brown; head darker brown; elytra, legs and antennae yellow; posterior margin of elytra dark.

Head: 0.42 mm long, 0.50 mm wide; eyes not prominent; slightly shorter than temples; sides of fore-head deeply emarginate; sides of clypeus nearly parallel; apical edge of clypeus even; without granules at angles; setiferous punctation deep and dense; interstices between punctures less than half as wide as diameter of punctures; small area at base of antennae and midline on vertex impunctate; without microsculpture; surface polished and shiny.

Antennae as long as head; second antennomere globular and thick; thicker than three following antennomeres; triangular third antennomere shorter and smaller than second; fourth antennomere as wide as third, but shorter and wider than long; following antennomeres increasing in width; fifth to eighth antennomeres wider than long; nineth and tenth antennomeres nearly quadrate.

Pronotum: 0.57 mm long, 0.51 mm wide; widest at anterior angles; evenly convergent to rounded posterior angles; setiferous punctation deep and dense; still denser and deeper than on head; interstices between punctures less than half as wide as diameter of punctures; narrow midline impunctate; without microsculpture; surface polished and shiny.

Elytra: 0.56 mm long, 0.50 mm wide; with weak coriaceous ground-sculpture; setiferous punctation fine and less deep than on pronotum and head.

Abdomen with large setiferous punctation; nearly as deep and dense as on pronotum; narrow midline on posterior tergites impunctate.

Protibia: 0.27 mm long, 0.08 mm wide; with 8 spines at outer edge; WLR: 3.0; comb at inner edge visible throughout its total length; posterior face with few yellow setae.

Aedeagus with short, thick and triangular apical lobe; nearly as thick as basal lobe; inner edge of apical lobe without sensillae.

Etymology: The specific name is a combination of the epithet in and the Latin word describere meaning not described. The name refers to the confusion between this species and O. exiguus   during my studies.

Osoriellus latipes ( GRAVENHORST, 1806)   new combination

( Figs 74 View Fig A-C, 99A)

Oxytelus latipes GRAVENHORST, 1806: 198  

Osorius mundus SHARP, 1887: 432   new synonymy

Type material examined: America septentrionalis: female without further data (lectotype in ZMHB); Mexico: Mexico City, 2 males, leg. Flohr (syntypes of O. munus   in BMNH)   .

Diagnosis: The species resembles O. brevicornis   , O. rugipennis   and O. neotropicus   due to the structure and punctation of the pronotum. It can be easily distinguished from those species by the long antennae with elongate second and third antennomere. In contrast to O. latipes   , O. rugipennis   and O. brevicornis   , O. neotropicus   has a digitate protibia. It can be also confused with O. mexicanus   and O. cordovensis   , but O. latipes   has an extremely fine netlike microsculpture that is absent in the other two species. The two syntypes of O. latipes   are damaged. I selected the smaller one as lectotype. It seems that both type specimens are not conspecific.

Description: Length: 6.6 mm. Colouration: Dark red; pronotum and elytra lighter red; legs and antennae yellow. Head: 0.90 mm long, 1.35 mm wide; eyes slightly prominent; as long as temples; vertex densely and deeply punctate; on average, interstices between punctures half as wide as diameter of punctures; wide midline with sparser punctation or partly impunctate; area at base of antennae impunctate and without microsculpture; surface polished; surface of vertex with distinct netlike microsculpture; slightly shiny; supraocular area densely covered by striae and granulate punctures.

Antennae with second antennomere oblong; distinctly longer than wide and as long as conical third; following three antennomeres quadrate and as wide as preceding two antennomeres; antennomeres 7 to 10 distinctly wider than preceding antennomeres, but still more or less quadrate.

Pronotum: 1.30 mm long, 1.40 mm wide; widest at anterior angles; approximately parallel in anterior half; distinctly convergent in posterior half; at posterior edge approximately half as wide as at anterior edge; lateral and posterior margin fine; with irregular and dense setiferous punctation; longitudinal row of 8 to 10 punctures on each side of wide impunctate midline; on average, interstices between lateral punctures as wide as diameter of punctures or slightly shorter; with few areas more sparsely punctate; anterior edge without margin, but with transverse row of dense punctures; surface with extremely weak netlike microsculpture; nearly polished.

Elytra: 1.50 mm long, 1.40 mm wide; with dense and distinct coriaceous ground-sculpture; irregular rows of punctures hardly visible between ground-sculpture.

Abdomen with dense setiferous punctation, setae much longer than setae on pronotum; surface with distinct netlike microsculpture.

Protibia: 0.56 mm long, 0.20 mm wide; 10 spines at outer edge; apical spines not inserted on digits; WLR: 4.0; in posterior aspect, comb of inner emargination partly covered in middle; posterior face densely covered by moderately long setae.

Aedeagus with long apical lobe and acute apex; without sensillae at inner edge.


American Museum of Natural History


The Educational Science Museum [=Kuwait Natural History Museum?]














Osoriellus indescriptus

Irmler, Ulrich 2014

Osorius mundus

SHARP, D. 1887: 432

Oxytelus latipes

GRAVENHORST, I. L. C. 1806: 198