Matskási István (szerk.): A Magyar Természettudományi Múzeum évkönyve 90. (Budapest 1998)

Makhan, D.: Three new genera and two new species of Hydrochidae from different parts of the World (Coleoptera)

Rishwanius richten (BRUCH) comb. n. (Fig. 17) Hydrochus richteri BRUCH, 1906: 273. Type. Holotype in Koninklijk Belgisch Instituut voor Natuurwetenschappen, Brussels, Belgium. This specimen is from Argentina. Distribution. Argentina. Diagnosis. Holotype male. Body elongate oval, length, 2.7 mm, width 1.0 mm. Colour of head, pronotum and scutellum black, colour of elytra brown, with blue-green metallic gloss and with large brown striai punctures. Head with coarse punctures. Pronotum longer than wide, lateral area smooth, on disc with 5 deep depressions; 3 large and suboval depressions of them situated in the middle, 2 large suboval ones along each lateral side. Elytra widest at middle, lateral area smooth, striai punctures wider than interstriae, interstriae slightly convex, apical hole absent. Elytral length 1.6 mm. Male genitalia (Fig. 17 is from the holotype): páraméra longer than basal piece, median lobe shorter than the páraméra. Remarks.This species is very similar to Rishwanius soesilae (MAKHAN) but there is a difference in the male genitalia: in R. soesilae (MAKHAN) the median lobe is widened to apex while the median lobe in R. richteri (BRUCH) is narrowed to apex.