Helophorus Fabricius 1775
Creators: name: Bilton, David T.
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Helophoridae
Helophorus

description: Key to the Afrotropical species of Helophorus   
1 Antennae 9-segmented............................................. 2  
– Antennae 8-segmented............................................. 4  
 2 Pronotal internal and middle intervals smooth, granulation reduced to pores and setae over most of surface (Figs 1D & 3C); median lobe of aedeagus with struts as long as tube (Fig. 3G); habitus relatively robust (Fig. 1D), body length 3.45–4.0 mm.............................................................. H. cooperi Orchymont, 1947   
– Pronotal internal and middle intervals with evident granulation over most of surface (Figs 1A & G, 3A & F); median lobe of aedeagus with struts distinctly shorter than tube....................................................... 3  
 3 Granulation on pronotal internal and middle intervals weaker (Figs 1A, 3A); prontoal submedian groove more strongly angled medially (Fig. 3A); parameres relatively straight, with evenly pointed tips (Figs 2A–B); body size smaller, 2.60–3.50 mm; aedeagus smaller, 0.45 mm.... H. aethiopicus Régimbart, 1907   
 – Granulation on pronotal internal and middle intervals stronger (Figs 1G, 3F); pronotal submedian groove more weakly angled medially (Fig. 3F); paramere tips more broadly rounded (Fig. 3L); body size larger, 3.15–3.85 mm; aedeagus larger, 0.55 mm...................................................................  H. simiensis sp. nov.    
 4 Aedeagus very large, 0.78–0.85 mm, parameres with acuminate tips (Fig. 2K); pronotal intervals raised and granulate (Figs 1F, 3E); body robust (Fig. 1F) and relatively large, 3.25–4.55 mm; species from East African Rift.................................  H. nyandaruaensis sp. nov.    
– Aedeagus smaller, maximum length 0.66 mm, paramere tips various, but not strongly acuminate (Figs 2C–F, H–J); pronotal intervals flatter (Figs 1B–C, E, 3B, E, 4C–F)........................................................................ 5  
 5 Pronotal submedian groove broader, granulation on middle and internal intervals weaker (Figs 1B–C, 3B, 4C, E); walls of pronotal grooves straighter and sharper (Figs 4C, E); punctures of elytral striae larger and intervals narrower and more arched apically (Fig. 4G); aedeagus smaller, 0.50–0.55 mm, parameres with relatively narrow apices (Figs 2C–F)...................................................... H. aethiops J. Balfour-Browne, 1954   
 – Pronotal submedian groove narrower, granulation on middle and internal intervals stronger (Figs 1E, 3D, 4D, F); walls of pronotal grooves more rounded and indistinct (Figs 4D, F); punctures of elytral striae smaller and intervals broader and flatter apically (Fig. 4H); aedeagus larger, 0.58–0.66 mm, parameres usually with relatively broad apices (Figs 2H–J).......................................................  H. brumopluvialis sp. nov.
description: Published as part of Bilton, David T., 2023, Out of the Palaearctic: the Helophorus water beetles of the Afrotropical Region (Coleoptera: Helophoridae), pp. 249-264 in Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) (Acta. Ent. Mus. Natl. Pragae) 63 (2) on page 262, DOI: 10.37520/aemnp.2023.014, http://zenodo.org/record/10134093