Eleusis frater ( FAUVEL, 1864 )

Irmler, Ulrich, 2017, The Neotropical species of the genus Eleusis LAPORTE, 1835 with description of the new genus Eleusima (Coleoptera: Staphylinidae: Osoriinae), Beiträge Zur Entomologie = Contributions to Entomology 67 (2), pp. 275-318 : 298

Eleusis frater ( FAUVEL, 1864)

Figs 26 A-C,31A

Isomalus frater FAUVEL, 1864: 35

Isomalus agilis SHARP, 1876: 410 new synonymy

Eleusis brasiliana WENDELER, 1955: 188 new synonymy

Type material examined: female, Holotype: Venezuela: Caracas, without more data ( IRSNB) . Holotype of E. brasiliana : Brazil: Espirito Santo, Affonso Claudio, Laranja de Terra , female, 27.9.1928, leg. Condé ( ZMH) . Two syntypes of E. agilis : Brazil: Amazonas, Tefé (Ega), 1 male, 1 female ( BMNH) .

Additional material examined: Venezuela : Caracas , without more date, male (coll. Kraatz) ( SDEI); Peru: Paso Dept. Villa Rica Rd. (10°47.6'S, 75°18.54'W), 1475 m elev. flight intercept tap, male, 15.- 18.10.1999, leg. R. Brooks, D. Brzoska # PERU 1B99030C ( KNHM) .

Diagnosis: With 4.3 mm length, the species is smaller than the other species of the group except the equally sized E. panamaensis . It also differs from the other species by the totally black or dark brown colouration which corresponds with the colouration of E. panamaensis . The E. agilis types are slightly lighter brown. However, this might be referred to the teneral stage of the specimens, because the aedeagus shows no difference to the totally black specimen from Peru. In contrast to E. panamaensis , the head has only remains of microsculpture. The punctation is deeper and denser, and the aedeagus is distinctly shorter and thicker.

Description: Length: 4.3 mm. Colouration: totally black; elytra, abdomen, legs and antennae dark brown.

Head: 0.57 mm long, 0.60 mm wide; eyes not prominent; postocular sides twice as long as eyes; preocular sides parallel; anterior margin of frons widely triangular; central part very slightly prominent; supraocular groove deep; punctation moderately dense and deep; uniform; interstices between punctures twice to three times as wide as diameter of punctures; setiferous puncture at each end of supraocular groove; another pair of setiferous punctures on each side of central frons; in supraocular grooves and adjacent areas close to base of antenna and close to neck with remains of microsculpture; most parts of vertex and frons without microsculpture; surface shiny.

Antennae slightly longer than head; first antennomere slightly thicker than three following antennomeres; fourth to tenth antennomere slightly increasing in width; fourth slightly longer than wide; tenth quadrate; eleventh antennomere nearly twice as long as tenth; fifth to eleventh antennomere pubescent; all antennomeres with apical setae.

Pronotum: 0.52 mm long, 0.60 mm wide; widest at anterior angles; in anterior half nearly parallel; in posterior half narrowed in continuous curve to posterior angles; anterior angles sharply rounded; at posterior margin, central part slightly prominent and margined by short ridges; without distinct angles; at anterior angles without short grooves; punctation sparser and weaker than on head; interstices between punctures three to four times as wide as diameter of punctures; several setiferous punctures along lateral margin; pair of setiferous punctures at anterior margin close to anterior angles; punctures inserted in deep impression; surface nearly polished; with remains of weak microsculpture at anterior angles and along lateral margin.

Elytra: 0.74 mm long, 0.74 mm wide; continuously divergent from humeral angles to posterior angles; humeral angles nearly rectangular; posterior angles widely rounded; punctation as sparse and deep as on pronotum; in central position at each side of suture with setiferous punctures; at lateral margin, remains of microsculpture; disc nearly without microsculpture; polished.

Abdomen weakly punctate; on each segment transverse row of setiferous punctures; transversely striate microsculpture weak; surface shiny.

Aedeagus in lateral aspect thick; shortly narrowed to obtuse apex; in ventral aspect, central lobe nearly parallel; numerous sensillae in central and apical area; parameres slender; shorter than central lobe; apical transparent lobe only slightly widened; few microsensillae at apex.

Figures

Fig. 24–27: E. peruviana (24), E. panamaensis (25); E. frater (26), E. elongata (27): aedeagus in lateral (A) and ventral (B) view,