Holotrochus lobatus, 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 : 169-170

Holotrochus lobatus sp. nov.

( Figs 13 , 18F )

Type locality. Panama, Province Chiriqui, La Fortuna .

Type material. HOLOTYPE:, ‘ Panama, prov. Chiriqui, La Fortuna Cont. Divide Trail (8°47.76’N, 82°14.75’W), montane forest, beating, 7.IX.2010, leg. L. Sekerka’ ( BMNH).

Diagnosis. This species can be easily identified by the specific structure of the anterior edge of the head. A similar structure is found also in H. trilobatus Irmler, 2010 from Argentina. However, in H. trilobatus the trilobate structure is placed behind the clypeus between the base of antennae, whereas in H. lobatus sp. nov. it borders the anterior edge of the head. Based on the shape of the lateral margin, the species might be placed in the H. picescens group. In this respect it also differs from H. trilobatus in a finely margined anterior edge of the pronotum.

Description. Length: 4.1 mm. Colouration dark brown; legs and antennae light brown.

Head 0.39 mm long, 0.69 mm wide; shape more or less transversely rectangular; eyes not prominent and as long as temples; anterior edge bisinuate; with central triangular lobe; punctation fine and sparse; on average, interstices between punctures more than twice as wide as diameter of punctures; isodiametric microsculpture weak, but distinct; surface moderately shiny.

Antennae with thick basal antennomere; second antennomere only half as wide as first and only half as long as conical third antennomere; following antennomeres slightly increasing in width; fourth antennomere quadrate; tenth only slightly wider than long.

Pronotum 0.75 mm long, 0.92; widest closely behind widely rounded anterior angles; evenly and slightly narrowed to more or less rectangular posterior angles; lateral margin fine; slightly thicker at anterior angles; ending in elevated curve at anterior angles; anterior and posterior edge without margin; punctation fine and sparse; size and density of punctures increasing from anterior to posterior edge; on average, interstices twice as wide as diameter of punctures; isodiametric microsculpture weak; surface moderately shiny.

Elytra 0.93 mm long, 0.99 mm wide; with coriaceous ground sculpture; punctation still finer and sparser than on head and pronotum: nearly invisible in coarse ground sculpture.

Abdomen with punctation deeper and denser than on fore-body; net-like microsculpture more distinct than on pronotum and surface less shiny.

Aedeagus with short and slender parameres; parameres as long as short apical lobe; apical lobe at inner edge of apex with short and minute tooth; inner edge with striate structure; endophallus with two long teeth and short wide torsions.

Etymology. The specific name is Latin adjective, lobatus , meaning lobed and referring to the bisinuate anterior edge of the head with two wide outer lobes and a triangular central lobe.

Distribution. Known only from the type locality.

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.