Holotrochus tortilis, Irmler, 2013

Irmler, Ulrich, 2013, New species of the genus Mimogonia and Holotrochus from South America (Coleoptera: Staphylindae: Osoriinae), Acta Entomologica Musei Nationalis Pragae 53 (1), pp. 155-176 : 165-166

Holotrochus tortilis sp. nov.

( Figs 12 , 18B )

Type locality. Bolivia, Province Beni, Guayaramerin .

Type material. HOLOTYPE:, ‘ Bolivia, Prov. Beni, Guayaramerin (65°22.07’ W, 10°49.25’ S), banks of the Rio Marmoré, sampled by Berlese method, 26.11.1966, leg. J. Balogh’ ( HNHM) . PARATYPES: 1 ♀, from the same location as the holotype ( HNHM); 1, ‘ Suriname, Albina (54°03.25’ W, 5°30.04’ N), 01.06.1981, leg. D. Balázs’ ( UIC) .

Diagnosis. This species certainly belongs to the Holotrochus minor group due to the same combination of character as mentioned above under H. paraguensis sp. nov.. Concerning the structure of the fore-body, the two species H. tortilis sp. nov. and H. paraguensis sp. nov. are mainly distinguished by the shape of the pronotum and the shape of the shoulders of elytra. Furthermore, the elytra in H. tortilis are slightly wider and the punctation is slightly coarser than in H. paraguensis sp. nov.

Description. Length: 3.2 mm. Colouration dark brown; small posterior margin of pronotum lighter reddish; legs red; antennae yellow.

Head 0.38 mm long, 0.55 mm wide; eyes slightly prominent, as long as temples; with supraocular margin continuing to base of antennae; within margin, row of 4 setiferous punctures; on a line between posterior edge of eyes, four setiferous punctures; interstices between inner setiferous punctures nearly twice as wide as distance between inner and outer punctures; punctation moderately deep and dense; at clypeus denser than on vertex; on average, interstices between punctures as wide as diameter of punctures; with sparse micro-punctation between normal punctures; surface without microsculpture, polished and shiny.

Antennae slightly longer than head; second antennomere globular; distinctly smaller than first and distinctly wider than conical third antennomere; third antennomere 1.5 times longer than second; antennomere 4 to 6 more or less quadrate only slightly increasing in width; seventh antennomere distinctly wider than sixth; following antennomeres increasing in width; tenth antennomere more than twice as wide as long.

Pronotum 0.55 mm long, 0.71 mm wide; widest in middle; more narrowed to posterior angles than to anterior angles; sides distinctly margined from posterior angles to anterior angles; lateral margin visible throughout its total length and continuing to front edge; punctation deep and dense; interstices between punctures on most parts as wide as diameter of punctures; near front angles with sparser punctation; narrow midline in posterior half impunctate; without microsculpture; surface polished and shiny.

Elytra 0.65 mm long, 0.73 mm wide; shoulders more or less rectangular, with short prominent tooth; punctation deep, dense, and partly coriaceous; with coriaceous ground sculpture; surface less shiny than pronotum.

Abdomen finely and densely punctate; with deep and dense net-like microsculpture, in particular on tergite VII; surface matte; last sternite triangular with few lateral punctures.

Aedeagus with acute apex pointing reverse; endophallus with two large torsions; parameres more or less straight; slightly outreaching apex of central lobe.

Etymology. The specific name is the Latin adjective tortilis meaning “twisted” and refers to the twisted endophallus of the aedeagus.

Distribution. Known only from Bolivia and Suriname.

Figures

Figs 12–15. 12 – Holotrochus tortilis sp. nov.; 13 – H. lobatus sp. nov.; 14 – H. agostii sp.nov.; 15 – H.pseudoleticiae sp. nov. Body parts:A – aedeagus; B – antenna; C – last sternite. Scale bar: 0.1 mm.

Fig. 18. Head, pronotum, and elytra of Holotrochus Erichson,1839 showing shape, punctation, and microsculpture.A – H. paraguensis sp. nov.; B – H.tortilis sp. nov.; C – H.hamatus sp. nov.; D – H.yanuniensis sp. nov.; E – H. mrazi sp. nov.; F – H. lobatus sp. nov. Scale bars: 0.5 mm.