Holotrochus mrazi, 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 : 169

Holotrochus mrazi sp. nov.

( Figs 9 , 18E )

Type locality. Brazil, Province Minas Gerais, São Paolo .

Type material. HOLOTYPE:, ‘ Brazil, Minas Gerais, Sao Pãolo, June 1914, leg. Mraz’ ( NMPC) . PARATYPES: 2 ♀♀, with same data as holotype ( NMPC, UIC) .

Diagnosis. The species is closely related to H. vianai and H. hamatus sp. nov. in shape, punctation, and absence of microsculpture of fore-body.All three species are characterised by the specific structure of the aedeagus with a minute tooth on the inner side of the apex and the spiralled apical part of the endophallus. Holotrochus mrazi sp. nov. is distinctly longer than the two other species that are only 4.2 and 4.5 mm long. Without dissecting the aedeagus, a certain identification is not possible. In contrast to H. hamatus sp. nov. and H. vianai , the apical spiral part of the endophallus is larger and thicker and has more coils.

Description. Length: 4.9 mm. Colouration black, elytra dark reddish, legs and antennae light brown.

Head 0.40 mm long, 0.84 mm wide; eyes slightly prominent; 1.5 times as long as temples; shape of fore-head semicircular with slight central emargination; punctation of vertex dense; on average, interstices between punctures smaller than diameter of punctures; between normal punctures with sparse micro-punctation; clypeus with remains of transverse microsculpture; vertex without microsculpture; surface polished and shiny.

Antennae short and thick; slightly longer than head; second antennomere globular; third antennomere conical and nearly twice as long as second; following antennomeres wider than long; antennomeres 6 to 11 wider than preceding antennomeres; penultimate antennomere nearly twice as long as wide.

Pronotum 0.90 mm long, 1.18 mm wide; widest in anterior third; anterior angles obtuse and slightly prominent; anterior edge emarginate, but with slight central prominence; sides in posterior half evenly narrowed to posterior angles; posterior angles obtusely rounded; lateral margin continuing to front edge; only central prominence not margined; punctation even, less dense, but as deep as on head; close to posterior edge denser than in anterior half; interstices between punctures in anterior half 2–3 times as wide as diameter of punctures; with indistinct impunctate midline in posterior half; at posterior angles with indistinct depression.

Elytra 1.05 mm long, 1.16 mm wide; with deep coriaceous ground sculpture; punctures larger than on pronotum, but hardly visible in deep ground sculpture; scutellum semicircular.

Abdomen sparsely punctate and with weak net-like microsculpture.

Aedeagus hook-like at apex; apex strongly sclerotized; shortly obtuse and at inner edge of apex with short minute tooth; endophallus sack-like at base and spiralled at apex.

Etymology. The specific name refers to the collector of the species, Jaro Mráz (*1880– †1927).

Distribution. Known only from the type locality.

Figures

Figs 8–11. 8– Holotrochus yasuniensis sp. nov.; 9 – H. mrazi sp. nov.; 10 – H. paraguensis sp. nov.; 11 – H. hamatus sp. nov. Body parts:A – aedeagus; B – antenna, C – tergite XII, D – 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.