Merizomena

Muilwijk, Jan, Felix, Ron & Anichtchenko, Alexander, 2022, A taxonomic revision of the genus Merizomena Chaudoir, 1873 (Coleoptera: Carabidae: Lebiini), Baltic Journal of Coleopterology 22 (1), pp. 1-54 : 5-6

Subgenus Merizomena s.str.

Type species: Merizomena (s.str.) basalis ( Chaudoir, 1852)

Description. Small to medium sized Lebiini (BL: 5–7.5 mm); Body moderately convex. Head dark, pronotum red or brownish, elytra bicolored: basal part red, distal part black, sometimes with violet or bluish metallic lustre; ventral side of the head partly red, partly black, in all cases anterior parts of genae and gula black; thorax red; ventrites black; appendages in most specimens with dark femora and antennae at least partly darkened.

Head. Rather large, frons and vertex with punctures and pubescence, scattered setae on posterior side of vertex; tempora with long hairs. Maxillary palpi with basal segment thickened, with 1 apical seta and 1 (in M. tricolor ) or 2 (in M. basalis ) basal setae; penultimate maxillary palpomere short. Mentum punctate, with acute lateral lobes clearly longer than median tooth. Genae punctate, with laterally some black setae. Antennae moderately slender.

Thorax. Pronotum more or less cordate; covered with punctures and erect pubescence. Prosternum and proepisterna with fine punctures and pubescence; coarser on mesosternum, metepisterna, metasternum and epipleura. Prosternal process not bordered in posterior part; with a pair of long setae in M. tricolor and several pairs in M. basalis . Metacoxae punctate, with two setae along lateral side.

Muilwijk J., Felix R., Anichtchenko A.

Abdomen. Elytra oblong­oval, slightly convex. Basal border interrupted at level of the 3 th or 4 th stria. Sutural apical angle nearly right, without a small dent. Elytral apical border with a few punctures with hairs in M. tricolor and smooth in M. basalis . Umbilicate series continuous, consisting of 13–15 pores. Interval 3 with one preapical pore. Ventrites punctate; especially laterally and on the anal ventrite yellow hairs. Anal ventrite with 2 pair of setae along apical margin.

Legs. Stout; tarsi on ventral side with dense short bristles and at dorsal side some hairs.

Median lobe. With one copulatory piece.

Female genitalia. Gonocoxite 1 without setae, gonocoxite 2 with setae in the apical quarter. Laterotergite IX narrow, semi­circular and highly chitinized.

Comparative notes. Species of this subgenus are characterized by the incomplete basal border of elytra, the shape of the copulatory piece and dark head and black ventrites.