Eleusis LAPORTE 1835
Creators: name: Irmler, Ulrich
Publisher: name: Zenodo
Year: 2017
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Staphylinidae
Eleusis

description: Key to species of the genus Eleusis  second; third antennomere nearly twice as long as second; following antennomeres shorter than third and increasing in width; fourth antennomere nearly twice as long as apical width; tenth as long as apical width; fourth to eleventh antennomeres pubescent and with few long apical setae.  
Pronotum: on average, 1.28 mm long, 1.43 mm wide; sides in anterior half parallel; in posterior half continuously narrowed to posterior angles; at posterior angles only half as wide as at anterior angles; short groove at each side margined by sharp ridge; central part slightly prominent posteriad; at anterior angles with deep short groove; anterior angles emarginate; depth of emargination varying corresponding to depth of groove; punctation as deep and sparse as on posterior vertex of head; on average, interstices between punctures three times as wide as diameter of punctures; setiferous punctures in anterior grooves, along lateral margin, and one large setiferous puncture at beginning of posterior third; pairs of setiferous punctures at anterior margin close to anterior angles; elongate microsculpture similarly dense and deep as on head; surface moderately matt.  
Elytra: on average, 1.52 mm long, 1.52 mm wide; slightly widened to posterior angles; humeral angles obtusely angled; punctation similarly dense and deep as on pronotum; setiferous punctures along lateral margin; one setiferous puncture in central position on each side of suture; elongate microsculpture as dense and deep as on pronotum; surface moderately matt.  
Abdomen impunctate except transverse rows of setiferous punctures on each abdominal segment; transverse reticulate microsculpture weak; surface shiny.  
Aedeagus elongate; in lateral view aspect, shortly acute; central lobe in anterior half with numerous sensillae and in apical third with minute diagonal striae; in ventral aspect, apex slightly emarginate; parameres slightly shorter than central lobe; with widened transparent apical lobe; at apical margin with minute setae; few sensillae on transparent apical lobe and at base of scape.  
 Etymology: The species name honours Tim Struyve, who found the species in Panama.   
1 Sides of pronotum interrupted by a short emargination followed by short tooth...................................................... 2  
– Sides not interrupted; posterior half continuously narrowed to posterior angles.................................................... 16  
2 Elytra with at least two pairs of setiferous punctures................................................................................................... 14  
– Elytra with one pair of setiferous punctures.................................................................................................................... 3  
3 Larger than 5.0 mm, elytra reddish brown...................................................................................................................... 4  
– Not longer than 4.5 mm, elytra reddish or light brown to yellowish with dark posterior margin or totally dark brown to blackish................................................................................................................................................................ 5  
 4 Antennae shorter, as long as head and half of pronotum combined, aedeagus thick and stout, in ventral aspect, apex rounded.................................................................................................................................... E. castanea spec. nov.   
 – Antennae longer, as long as head and pronotum combined; aedeagus slenderer, in ventral aspect, apex triangular...................................................................................................................................................... E. ecuadoriensis spec. nov.   
5 Elytra light reddish brown, with dark spot along suture, pronotum with narrow impunctate midline, elytra distinctly longer than wide.................................................................................................................................................................. 6  
– Elytra dark brown without darker spot or pale with darker posterior margin and sides; pronotum without impunctate midline, elytra quadrate, wider than long or only slightly longer than wide....................................................... 7  
 6 Head and pronotum with pairs of impressions, slightly smaller, 3.8 – 4.0 mm long........... E. rufipennis spec. nov.   
 – Head and pronotum without impressions; slightly larger, 4.2 mm long..................................... E. genieri spec. nov.   
 7 First antennomere black; prominence of aedeagus short and close to apex........................ E. hondurana spec. nov.   
– First antennomere yellow; prominence of aedeagus in central position, triangular or extremely elongate........... 8  
 8 Prominence of aedeagus slender and elongate; nearly as long as apex of parameres............ E. boliviana spec. nov.   
– Prominence of aedeagus widely triangular or nearly absent......................................................................................... 9  
9 Aedeagus stout and broad; apical half of central lobe as wide as or wider than basal half; apex broadly obtuse..... 10  
– Aedeagus slender; apical half of central lobe smaller than or equally wide as basal half; apex semicircular or slightly acute.................................................................................................................................................................................... 11  
 10 Apex of aedeagus broadly obtuse.................................................................................. E. interrupta (ERICHSON, 1840)   
 – Apex of aedeagus with wide lobes..................................................................................................... E. andina spec. nov.   
11 Smaller, 2.2 – 2.9 mm long, elytra yellow to light brown with blackish posterior margin, with at least slight central prominence of aedeagus................................................................................................................................................... 13  
– Larger, 3.1 – 3.5 mm long................................................................................................................................................. 12  
 12 Elytra as black as head and pronotum, central prominence of aedeagus nearly absent, only marked by concentration of sensillae, apex of paramere without sensillae...................................................................... E. nigrita spec. nov.   
 – Elytra dark brown to yellowish with black posterior margin, central prominence of aedeagus large, nearly semicircular, apex of paramere with fringe of short setae......................................................... E. nigerrima FAUVEL, 1864   
 13 Smaller, 2.2 – 2.4 mm, head and pronotum brown, central prominence of aedeagus extremely weak...................................................................................................................................................................................... E. fauveli spec. nov.   
 – Larger, 2.5 – 2.9 mm, head and pronotum blackish, central prominence of central lobe weak, apex of parameres without marginal setae........................................................................................................... E. humilis ERICHSON, 1840   
 14 Totally black, punctation of head weak.................................................................................... E. breviceps SHARP, 1887   
– At least with few yellow parts, extremely variable in colouration, but never totally black...................................... 15  
 15 Head coarsely punctate, interstices between punctures less than half as wide as diameter of punctures............................................................................................................................................................................ E. insignis SHARP, 1887   
 – Punctation of head weaker, interstices between punctures at least as wide as diameter of punctures....................................................................................................................................................................................... E. scita SHARP, 1887   
 16 Slender species, not depressed in dorso-ventral direction; left mandible with broad and thick tooth.................................................................................................................................................................................... E. elongata spec. nov.   
– Species depressed in dorso-ventral direction, left mandible with acute tooth......................................................... 17  
17 Totally black....................................................................................................................................................................... 18  
– Only partly black, variable in colouration, but never totally black............................................................................ 19  
 18 Head with dense microsculpture and without punctuation............................................... E. panamaensis spec. nov.   
 – Head with polished parts and distinctly punctate.................................................................. E. frater (FAUVEL, 1865)   
 19 Pronotum reddish, elytra in anterior half reddish, in posterior half dark, smaller than 5.0 mm............................................................................................................................................................................................ E. rufula SHARP, 1887
description: Published as part of Irmler, Ulrich, 2017, The Neotropical species of the genus Eleusis LAPORTE, 1835 with description of the new genus Eleusima (Coleoptera: Staphylinidae: Osoriinae), pp. 275-318 in Beiträge Zur Entomologie = Contributions to Entomology 67 (2) on pages 302-303, DOI: 10.21248/contrib.entomol.67.2.275-318, http://zenodo.org/record/5742497