Graptodytes exsanguis (Bedel, 1925) n. stat., a newly recognised species of diving beetle from North Africa,Corsica and Sardinia,with notes on other taxa of the varius/ignotus complex (Coleoptera: Dytiscidae)

Summary

A species of the genus Graptodytes Seidlitz, 1887 (varius/ignotus complex) is newly recognised and described based on recently sampled specimens from Corsica and Sardinia, and material in various collections from Algeria, Tunisia, Corsica and Sardinia. The name exsanguis, created by Bedel in 1925 for a variety of what he then called Hydroporus varius Aubé, 1838, is shown to be available for the newly recognised species, therefore named Graptodytes exsanguis (Bedel, 1925) n. stat. (type locality: Algeria, La Calle – nowadays El Kala). This species is similar in size and colour pattern to G. fractus (Sharp, 1882), from which it can be distinguished by strong differentiation of the male protarsal claws, features of the habitus and elytral punctation, and shape of the median lobe of aedeagus. Morphological features of G. exsanguis and G. fractus are illustrated, and pictures showing for each species the variability of habitus and median lobe are provided. For comparison, the habitus and median lobes of other species of the varius/ignotus complex are also illustrated. Habitat preferences of G. exsanguis are described based on field observations in Corsica and Sardinia, and a distribution map of validated records is presented. Analysis of a partial CO1 alignment yielded a basal and divergent position within the varius/ignotus complex for the sequenced G. exsanguis haplotypes from Corsica and Sardinia. Lectotypes are designated for Hydroporus varius var. exsanguis Bedel, 1925, Hydroporus fractus Sharp, 1882 and Graptodytes ignotus var. fallaciosus Guignot, 1932, and the latter is established as a junior synonym of G. fractus.