Holotrochus pubescens, Sharp, 1876

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 : 161-162

Key to the species of the Holotrochus pubescens group

The species of this group are characterised by the pubescent body and the margined anterior edge of the pronotum.

1. Small species, not longer than 2.5 mm. .......................................................................... 2

– Larger species, at least 3.0 mm. ..................................................................................... 3

2. Punctation of fore-body sparse and fine, interstices between punctures wider than diameter of punctures. ................................................................................ H. subtilis Sharp, 1876

– Punctation of fore-body coarse and dense, interstices between punctures much smaller than diameter of punctures. ............................................... H. danoffburgi Irmler, 2001

3. Pronotum widest close to posterior angles ( Fig. 17E ); evenly narrowed to smoothly rounded anterior angles, antennomeres 6 and 7 more or less quadrate ( Fig. 5 ). ............................. ......................................................................................................... H. siolii Irmler, 2001

– Pronotum widest close to middle; sides evenly narrowed to obtuse or rectangular posterior and obtuse anterior angles, antennomeres 6 and 7 either quadrate or wider than long. .... 4

4. Antennomeres 6 an 7 wider than long ( Fig. 4 ), pronotum evenly narrowed to posterior angles, posterior angles obtuse ( Fig. 17A ). ............................ H. pubescens Sharp, 1876

– Antennomeres 6 and 7 quadrate, pronotum with short emargination in front of posterior angles, posterior angles rectangular. .............................................................................. 5

5. Smaller species, 3.3 mm long ( Fig. 17D ). ............................................. H. adisi sp. nov.

– Larger species, 3.7 mm long ( Fig. 17B ). ............................. H. amazonicus Irmler, 1981

Figures

Fig. 17. Head, pronotum, and elytra of Holotrochus Erichson, 1839 showing shape, punctation, and microsculpture. A – H. pubescens Sharp, 1876; B – H. amazonicus Irmler, 1981; C– H. siolii Irmler, 2001; D – H. adisi sp. nov. Scale bars: 0.2 mm.

Figs 4–7. 4 – Holotrochus pubescens Sharp, 1876; 5 – H. siolii Irmler, 2001; 6 – H. amazonicus Irmler, 1981; 7 – H. adisi sp. nov. Body parts: A – aedeagus in lateral aspect; B – antenna. Scale bars: A – 0.1 mm, B – 0.5 mm.