Holotrochus yasuniensis, 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 : 168

Holotrochus yasuniensis sp. nov.

( Figs 8 , 18D )

Type locality. Ecuador, Province Orellana, Yasuni .

Type material. HOLOTYPE:, Ecuador, Orellana (77°08.05’W, 0°41.38’S), E. Cientifica Yasuni, collected by fogging, 20.04.2011, leg. J. Torres ( VAC, to be deposited in NHMW) . PARATYPE:, with same data as holotype ( UIC) .

Diagnosis. Concerning the size, punctation and microsculpture of the fore-body, H. yasuniensis sp. nov. resembles H. decumanus Irmler, 2005 from Central America that belongs to the H. rufopygus group. Holotrochus yasuniensis sp. nov. is characterised by the shape of the pronotum that seems to be unique in the Neotropical Holotrochus species. It can be identified easily by the slight lateral emargination in the anterior half.

Description. Length: 5.1 mm. Colouration black; legs and antennae light brown.

Head 0.50 mm long, 0.81 mm wide; eyes large and not prominent, slightly longer than temples; sides of clypeus narrowed to anterior edge in smooth convex curve; vertex evenly punctate; punctation on fore-head denser than posteriorly; supraocular area from base of antennae to posterior edge of eyes impunctate; several setae on supraocular carina and pair of setae on neck; neck setae in equal distance to eyes as interstice between setae; weak net-like microsculpture; surface slightly shiny.

Antennae as long as head and half of pronotum combined; first antennomere rectangular and thick, second oval and slightly smaller than first; conical third two times as long as second; fourth and fifth antennomere quadrate; following antennomeres slightly increasing in width; penultimate antennomere nearly twice as wide as long.

Pronotum 0.89 mm long, 1.17 mm wide; widest at middle; slightly narrowed to anterior and posterior angles; in anterior half smoothly emarginate; in posterior half slightly concave, but nearly straight; anterior angles distinctly prominent; thus, anterior edge widely emarginate; sides and most parts of anterior edge margined; in dorsal aspect, lateral margin visible throughout its total length; at anterior angles, margin distinctly thicker than laterally and at anterior margin; punctation moderately dense and deep; slightly deeper than on head; interstices between punctures irregular, but, on average, twice as wide as diameter of punctures; weak net-like microsculpture; surface slightly shiny.

Elytra 1.20 mm long, 1.26 mm wide; with even punctation; punctures larger and partly denser than on pronotum; on average, distance between punctures as wide as diameter of punctures; net-like microsculpture weak; meshes of microsculpture wider than on pronotum; surface slightly shiny.

Abdomen with sparser and weaker punctation than on fore-body; laterally and ventrally pubescent; net-like microsculpture denser than on fore-body; thus, surface matte; abdominal tergite VIII with smooth oval depression, depression without distinct border.

Aedeagus with similarly long basal and apical part; apical part in nearly rectangular angle to basal part; apical part carinate from base of parameres to acute apex: parameres sinuate; endophallus indistinct as short tube.

Etymology. The specific name is an adjective derived from the region of Yasuni where the species was collected.

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.