Coptotomus Say, 1830

Hendrich, Lars & Balke, Michael, 2020, A Baltic amber species of the diving beetle genus Coptotomus Say, 1830 (Coleoptera Dytiscidae: Coptotominae), Zootaxa 4895 (2), pp. 285-290 : 286

Genus Coptotomus Say, 1830

Type species: Coptotomus serripalpus Say, 1830: 30 .

Diagnosis. Medium sized species of Dytiscidae (total length 5.2–8.6 mm), dorsally with fine, dense puncturation; females with punctures of pronotum and base of elytron elongated into short, fine strioles, or in the Baltic species with longitudinal striae on pronotum and elytron. Colour yellow to pale red with dorsal surface variously marked ( Fig. 3A ) ( Larson et al. 2000). Miller & Bergsten (2016) provided the following diagnostic character combination: 1) pronotum with well developed lateral bead; 2) metacoxal lobes large and rounded with metacoxal lines not closely approximated; 3) prosternum and prosternal process in same plane; 4) pro- and mesotarsi distinctly pentamerous; 5) scutellum visible; 6) metatarsomeres I–IV with lobed ventral apical angles; 7) apical palpomere of both, maxillary and labial palps, distinctly bifid and 8) metatarsal claws subequal in length in both sexes.

Figures

FIGURE 3. Coptotomus longulus lenticus Hilsenhoff, 1980, USA, Ohio, Holmes (scale bar = 1 mm): A) habitus (dorsal side); B) Metasternum and metaventrite of C. longulus longulus (USA, Montana).