Pseudastenus barretoi Bernhauer, 1933

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 : 142

Pseudastenus barretoi Bernhauer, 1933

Figs. 36, 38 , 51

Pseudastenus barretoi Bernhauer, 1933: 520 (original description, type locality: “Barreto, Jujuy ”); Bachmann et al., 2017: 14

(mention syntype in the MACN).

Type material examined. Lectotype herein designated ( Figs. 36, 38 ). Male, dissected, deposited in FMNH, Argentina, Barreto, Jujuy, August 1929, don. Bruch. The male specimen in FMNH was designated as a lectotype and your designation label was added to the pin with the specimen. A paralectotype is deposited in MACN ( Bachmann et al., 2017). According to the labels, Bernhauer named the specimen at first as Astenus magnificus , but the manuscript name was not used and in the final description Bernhauer named the species Pseudastenus barretoi .

Diagnosis. The species is part of a group of species with short elytra, reduced hind wings and indistinct humeral angles. Actually, besides P. barretoi , two further species are known in this group: P. ribeirocostae and P. schubarti Eyes in P. barretoi Bernhauer, 1933 are less reduced (0.30 times as long as total head length) than in the two other species (0.20 times as long as total head length). Coloration in P. ribeirocostae and P. schubarti is more yellowish brown, whereas it is more blackish in P. barretoi except the yellow pronotum and posterior half of elytra.

Redescription. Body length: 3.38 mm. Coloration: Head, anterior half of elytra, and abdominal segments black: pronotum, posterior half of elytra, and posterior margin of tergite VII and base of tergite VIII yellowish; blackish part of elytra indistinctly continued along suture and laterally; legs and antennae yellowish. Head: 0.43 mm long, 0.47 mm wide; eyes moderately large; 0.28 times as long as head; postocular sides approximately 1.5 times as long as eyes; shape trapezoidal; much smaller at front than at base; anterior margin smoothly rounded, posterior margin straight; posterior angles rectangular; eyes approximately at median position between front and posterior margin; Pronotum: 0.44 mm long, 0.48 mm wide; widest at anterior fourth; angles rounded; strictly tapered to small neck; posteriorly convergent; at posterior margin one fourth narrower than at widest part. Elytra: 0.42 mm long, 0.45 mm wide; length of suture: 0.37 mm; without distinct humeral angles; humeral angles widely rounded; sides from humeral angles to posterior angles divergent; at posterior angles one fourth wider than at indistinct humeral angles; posterior margin triangularly bend to suture; lateral sides much longer than suture; setiferous punctures slightly larger than on pronotum; surface matt. Abdomen with dense setiferous punctation; setae black; longer than on forebody; pointing posteriad; Aedeagus elongate; 0.57 mm long; 4.6 times as long as wide; slightly converging to apex; sclerites 0.16 mm long; slightly s-shaped, at base more sclerotized than at apex.

Geographical records. Pseudastenus barretoi is only known from the type location in northern Argentina (Jujuy).

Biological notes. No information is given about the sampling habitats by Bernhauer (1933).

Figures

FIGURES 36–39. 36. Pseudastenus barretoi, lectotype, dorsal view (FMNH); 37. P. plaumanni, lectotype, dorsal view (FMNH); 38. Labels from the lectotype of P. barretoi (FMNH); 39. Labels from the lectotype of P. plaumanni (FMNH). 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.