Phylogenetic analysis of the genera of Haliplidae (Coleoptera) based on characters of adults

Selected external characters of adult representatives of all haliplid genera (Algophilus Zimmermann, Apteraliplus Chandler, Brychius Thomson, Haliplus Latreille, and Peltodytes Régimbart) were examined and analyzed phylogenetically. Small, subulate ultimate segments of the maxillary and labial palps, strongly reduced elytral suturai striae, distinctly asymmetrical parameres, and endophytic deposition of eggs are synapomorphies of Haliplidae excluding Peltodytes. The laterally compressed peristome, resulting in a peculiar shape and arrangement of mouthparts, extremely shallow maxillary fossae, and very large metacoxal plates which cover all but the last abdominal sternites are synapomorphies of Peltodytes. Complete absence of elytral suturai striae, reduction in length of elytral epipleurae, serrate meso‐ and metatibial spurs, transverse bulges on sterna V‐VII, elongate gonocoxosternal processes (Algophilus?) reduction of the fringe of setae of the left paramere are synapomorphic characters of a monophyletic unit comprising Algophilus, Apteraliplus and Haliplus. Incision of the terminal abdominal sternite, flat and parallel‐sided pronotum, long tarsal claws, and micropores on large parts of the body surface are synapomorphies of Brychius. The monophyly of Algophilus and Apteraliplus is self understood as both are monobasic genera. Haliplus is not monophyletic. The genus is only defined by characters which are plesiomorphic or which also apply to other haliplid genera. Algophilus, Apteraliplus and species of the subgenus Liaphlus together form a monophyletic unit which is characterized by the following synapomorphies: secondary genal line, digitiform appendage of left paramere, and strong, caudolaterally dilated apodemes of the gonocoxae. Algophilus is closely related to African species of Haliplus (Liaphlus) designated as group X by Zimmermann (1924). The generic status of Algophilus and Apteraliplus is not appropriate. These “genera”; were erected on the basis of some few, highly visible autapomorphous characters. Erection of new taxa based on such autapomorphous characters, without consideration of the monophyly of the groups from which these taxa are separated, is misleading in systematic work and should be discouraged.