Pseudastenus amazonicus Irmler

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: 149-151

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Pseudastenus amazonicus Irmler

sp. nov.

Pseudastenus amazonicus Irmler   , sp. nov.

Figs. 44 View FIGURES 40–45 , 53 View FIGURES 48–54

Material examined. Holotype. Male , dissected, deposited in INPA, labeled as holotype by Irmler. “ Brazil: AM, Manaus, Ilha de Marchanteria (3°15’S, 59°58W), 27.7,1981, floatingm meadow, #BE50B, leg. J. Adis ” GoogleMaps   . Paratype: 1 female deposited in UIC. Female, labeled as paratype by Irmler. Brazil: Manaus, L. Janauarí, 3.1972, leg. U. Irmler  

Diagnosis. The species can be differentiated from the other species of Pseudastenus   with elongate elytra by the totally light brown coloration of elytra and the only slightly darker coloration of the head. In contrast to all other Pseudastenus   species, the apical sclerites of the aedeagus have several hooks pointing laterally and not only one hook pointing backwards ( Fig 53 View FIGURES 48–54 ).

Description. Body length: 2.89 mm. Coloration: head light brown; pronotum lighter brown than head, nearly yellow; elytra slightly darker brown than pronotum, but lighter than head; abdomen brown; femurs brown, tibiae, tarsi and antennae yellow ( Fig. 44 View FIGURES 40–45 ). Head: 0.37 mm long, 0.41 mm wide; eyes moderately short; 0.24 times as long as total length of head; half as long as postocular length. Pronotum: 0.37 mm long; 0.46 mm wide; widest near anterior obtuse angles; apical and posterior margin curved; sides slightly convergentposteriad; with long black seta, each marking obtuse angles. Elytra: 0.46 mm long, 0.45 mm wide; humeral angles widely curved; wings developed; sides slightly curved, widest in the middle; posterior margin deeply emarginate; suture length only 0.9 times as long as lateral length; microtuberculate punctation larger than on head and pronotum; with loose pubescence; posterior margin with fringe of short black setae; Abdomen with normal punctation and denser pubescence than fore-body. Aedeagus 0.47 mm long; 4.50 times as long as apical width; widest shortly behind apex; anteriad divergent; sclerites 0.08 mm long; with broad base, narrowed in the middle and shortly widened to a bi-hooked apex ( Fig. 53 View FIGURES 48–54 ).

Etymology. The species name derived from the Brazilian state of Amazonas, where it was collected.

Geographical records. Pseudastenus amazonicus   was found in Central Amazonia along the Rio Solimões, Amazonas ( Brazil).

Biological notes. The two specimens of P. amazonicus   were collected in the inundation forest and floating meadows of the Rio Solimões.


Instituto Nacional de Pesquisas da Amazonia


Australian Museum