Eleusis mazureki, Irmler, 2019

Irmler, Ulrich, 2019, Additions to the Neotropical species of the genusEleusis LAPORTE, 1835 with description of new species (Coleoptera, Staphylinidae, Osorinae), Beiträge Zur Entomologie = Contributions to Entomology 69 (1), pp. 71-77 : 74

Eleusis mazureki spec. nov.

urn.lsid:zoobank.org.act: 220D0CEA-75CB-4537-BA0D-D95752582D34

Figs 1 a-c, 4A

Type material: Holotype, male: Peru, Dept. Consuelo, Manu rd. km 165, 12.10.1982, leg. L.E. Watrous & G. Mazurek, #FMHD 82-373 ( FMNH) . Paratypes: Peru: Cuzco Dept., Consuelo, Manu rd. km 165, rotten palm & leaf litter, male, female, 1.10.1982, leg. L.E. Watrous & G. Mazurek, #FMHD 82-313 ; same location and collectors, 2 females, #FMHD 11.10.1982 (3 FMNH, 1 UIC) .

Diagnosis: The species is part of the E. bicolor group of the Neotropical Eleusis species due to the shape of the pronotum with smoothly rounded sides, not interrupted by a short emargination behind the middle. Front angles with groove and one setiferous puncture adjacent at inner margin. It mostly resembles E. frater ( FAUVEL, 1864) and E. panamensis IRMLER 2017 in size and coloration. While the head of E. frater ( FAUVEL, 1864) has polished parts on the head and E. panamaensis IRMLER, 2017 has contiguous weak microsculpture, E. mazureki spec. nov. has dense and deep microsculpture with matt surface. Furthermore, the elytra are lighter yellowish, the head is more elongate with longer postocular space, and the shape of the aedeagus is distinctly different from that of both species.

Description: Length: 4.2 mm. Coloration: Dark blackish brown; elytra lighter yellowish in anterior half; abdomen lighter brown than head and pronotum; legs and antennae light brown.

Head: 0.64 mm long, 0.62 mm wide; eyes not prominent; shorter than postocular space; postocular sides slightly divergent to rounded posterior angles and 1.3 times as long as eyes; neck distinct; preocular sides shortly parallel to base of antennae; anterior margin of clypeus strongly convergent to straight central part; supraocular groove long and deep with two setiferous punctures at each end of the groove; more setiferous punctures along anterior margin of clypeus; two deep round depressions on central part between eyes; normal punctation deep and moderately sparse; interspace between punctures two to four times as long as diameter of punctures; microsculpture deep and dense; reticulation elongate; surface matt.

Antennae as long as head and half of pronotum combined; first antennomere longer and thicker than following antennomeres; second antennomere only half as long as first; third antennomere triangular, only slightly shorter than first; following antennomeres decreasing in length and slightly increasing in width; fourth antennomere longer than wide; tenth antennomere wider than long; eleventh antennomere nearly twice as long as wide; fourth to eleventh antennomere with yellow setae.

Pronotum: 0.52 mm long, 0.60 mm wide; sides approximately parallel in anterior half; strongly convergent in posterior half; at anterior angles with groove separated by carina from a second round groove at inner anterior margin; inner round groove with setiferous punctures; outer groove at angle with setiferous puncture posteriad; another setiferous puncture in posterior half at lateral margin; along anterior and posterior margin few further setiferous punctures; normal punctation as dense and deep as on head; microsculpture similar as on head but only elongate reticulate on central disc; at angles and along sides wavy reticulate; surface matt.

Elytra: 0.50 mm long, 0.66 mm wide; sides divergent to posterior angles; humeral angles distinct; shortly rounded; posterior angles rounded; posterior margin slightly curved with weak incision at suture; one setiferous puncture on central disc; few more setiferous punctures along lateral margin; normal punctation as dense and deep as on head and pronotum; micro-sculpture similarly deep and dense as on head and pronotum an with elongate reticulation; surface matt.

Abdomen with weak transverse reticulate microsculpture; punctation weaker and sparser than on forebody; surface shiny.

Aedeagus in lateral aspect with central lobe curved; with distinctly sclerotized ventral plate; on central part of ventral plate with slight prominence; apex triangularly widened; prominence with several sensillae; further sensillae adjacent to prominence; no endophallic structures visible; in ventral aspect, central lobe elongate with convergent apex; row of sensillae along midline and few further sensillae adjacent to it; parameres shorter than central lobe; slender; widened to transparent lobe at apex; transparent lobe with few micro-sensillae and one short seta.

Etymology: The species name honours one of the collectors who found it during his extensive collections in

South America.

Figures

Figs 1–3:Eleusis mazureki (1), E. dybasi (2), E. chiriquensis (3); aedeagus lateral (a) and ventral (b) aspect, antenna (c); scale bar 0.1 mm. –Fig. 4: Forebody showing shape and colouration ofEleusis mazureki (A), E. dybasi (B), E. chiriquensis (C); scale bar, 0.5 mm.