Pseudastenus ribeirocostae Busanello & Caron, 2020

Busanello, Dilson G. C., Irmler, Ulrich & Caron, Edilson, 2020, Revision of Pseudastenus Bernhauer, synonym with Xenasterides Newton and six new species (Coleoptera, Staphylinidae, Paederinae), Zootaxa 4755 (1), pp. 139-154 : 146-148

Pseudastenus ribeirocostae Busanello & Caron , sp. nov.

Figs. 40 , 48

Material. Holotype. Male, dissected, deposited in DZUP, labels: (1) “Sample-ID: CC2 F4F7/ Staphylinidae : Xenaster ” [white label, printed in black and handwritten]; (2) BRAZIL: PR: Reserva do Cachoeira /APA Guarequeçaba Moist Lowland / Forest ,sift. Litter , winklerextr. coll./ Bihn ; 20.7.-9-8[Aug.].[20]07” [white label, printed in black]; (3) “ DZUP / 270719 ” [white label, printed in black]; (3) “ HOLOTYPE / Pseudastenus ribeirocostae Busanello & Caron /det. E. Caron, 2019” [red label/ printed in black] . Paratypes: BRAZIL: 22 specimens from BRAZIL, Paraná ( DZUP)

Diagnosis. Among the species group with short elytra and reduced hind wings Pseudastenus ribeirocostae can be separated from P. barretoi by smaller eyes and from P. schubarti by the darker anterior half of elytra. Males of these two species are distinguished by the different arrangement of sclerites in the aedeagus.

Description. Body length: 3.30 mm. Coloration: Body yellowish brown, pronotum and appendices lighter, abdomen darker. Head 0.49 mm long, 0.49 mm wide; eyes small, very slightly prominent; 0.17 times as long as total length of head; 0.33 times as long as postocular length; approximately parallel; posterior margin straight; depressed on central vertex in front of neck. Pronotum 0.47 mm long, 0.49 mm wide; widest close to anterior angles; anterior margin slightly curved; posterior margin straight; sides convergingposteriad. Elytra 0.47 mm long, 0.38 mm wide; as long as pronotum, but conspicuously narrower than pronotum; sides slightly diverging posteriad; widest near the apex; humeral angles rounded; hind wings not developed; posterior angles curved; posterior margin strongly emarginate, exposing tergite II medially; suture 0.82 times as long as lateral side; microtuberculate punctation larger than on head and pronotum; with yellow pubescence pointing posteriad, longer than head and pronotum; posterior edge with fringe of sparse robust setae. Abdomen with dense punctation; with yellow pubescence pointing posteriad; pubescence conspicuously longer than on the rest of body. Aedeagus elongate; 0.68 mm long; 5.50 times as long as wide; median lobe with sides slightly converging towards to the apex, robust basal sclerites and pair of inconspicuous apical sclerites, 0.09 mm long; ejaculatory duct with two trifurcate accessorysclerites, proximal two times longer than distal ( Fig. 48 ).

Etymology. The specific name honors professor Dr. Cibele Stramare Ribeiro-Costa of the Federal University of Paraná (UFPR), specialist in seed beetles ( Chrysomelidae , Bruchinae ). She has started and encouraged the recent studies of staphylinid beetles in Brazil.

Geographical records. Pseudastenus ribeirocostae is known from the eastern regions of Paraná ( Brazil).

Biological notes. The specimens of Pseudastenus ribeirocostae were collected in leaf litter of cambisol and gleysol soils using the Winkler extraction.

Figures

FIGURES 40–45. Dorsal view. 40. Pseudastenus ribeirocostae sp. nov.; 41. P. ferrugineus sp. nov.; 42. P. latus sp. nov.; 43. P. oculatus sp. nov.; 44. P. amazonicus sp. nov.; 45. P. schubarti sp. nov. Scale bars: 2 mm.

FIGURES 48–54. Aedeagus of Pseudastenus, dorsal and lateral view, respectively, figures 51–54 including microscopic detail of basal slerites. 48. P. ribeirocostae sp. nov.; 49. P. ferrugineus sp. nov.; 50. P. latus sp. nov.; 51. P. barretoi; 52. P. oculatus sp. nov.; 53. P. amazonicus sp. nov.; 54. P. schubarti sp. nov. Scale bar: 0.3 mm.