Phaenostoma d’Orchymont, 1937

Gustafson, Grey T. & Short, Andrew E. Z., 2010, Redescription of the Neotropical water scavenger beetle genus Phaenostoma (Coleoptera: Hydrophilidae) with description of two new species, Acta Entomologica Musei Nationalis Pragae (suppl.) 50 (2), pp. 459-469 : 468

Key to the species of Phaenostoma d’Orchymont, 1937

1 Size greater than 2.8 mm. Elytral ground punctation not impressed in recessed ‘disc’ punctures ( Fig. 1 ). Parameres wider, nearly parallel-sided in basal ¾, slightly curved inward apically ( Figs. 2A, C, D ). ................................................................................................ 2

– Size less than 2.4 mm. Elytral ground punctation impressed in recessed ‘disc’ punctures ( Fig. 3 ). Parameres very narrow, arcuatelly bent inward from base to apex ( Fig. 2B ). ..... .............................................................................................................. P. kontax sp. nov.

2 Size generally larger (> 3.0 mm). Aedeagus with apex of parameres strongly sinuate ( Fig. 4A ). ...................................................................................... P. posticatum ( Sharp, 1887)

– Size generally smaller (<3.0 mm). Aedeagus with apex of parameres slightly inwardly curved ( Figs. 4 C–D). ..................................................................... P. stochasma sp. nov.

Figures

Fig. 1. Dorsal and ventral habitus of Phaenostoma posticatum (Sharp, 1887) (Costa Rica). Scale bar = 1.0 mm.

Fig. 2. Sternal process of Phaenostoma species. A – P. kontax sp. nov.; B – P. posticatum (Sharp, 1887); C – P. stochasma sp. nov.

Fig. 3. Elytron of Phaenostoma kontax sp. nov. A – entire elytron; B – enlargement of elytral surface.

Fig. 4. Aedeagi of Phaenostoma species. A – P. posticatum (Sharp, 1887) (Costa Rica); B – P. kontax sp. nov. (holotype); C – P. stochasma sp. nov. (holotype; Costa Rica); D – P. stochasma sp. nov. (paratype; Venezuela). Scale bar = 0.2 mm.