Two new species of the subgenus Pleurosticha of the genus Chrysolina (Coleoptera: Chrysomelidae) from the mountains of southern Siberia (Altai and Tyva)

Two new species from the subgenus Pleurosticha of the genus Chrysolina are described from the mountains of southern Siberia (Russia): Ch. reshetnikovi sp. nov. (Republic of Altai) and Ch. borisi sp. nov. (Republic of Tyva). Chrysolina reshetnikovi sp. nov. has a slightly convex body, a blue-green coloration of the upper side, regular puncture rows of the elytra and mostly flat elytral intervals, which distinguish this species from all species of the subgenus, except for Ch. shapkini Mikhailov et Gus’kova, 2013. The main distinguishing features of the male of the new species from Ch. shapkini are the strongly broadened tarsomeres 1–3, the pygidium with an impression along its entire length, the last abdominal sternite with a semicircular depression, and the apex of the aedeagus bent at 90°. Chrysolina borisi sp. nov. has a convex small body, black coloration of the upper side, femora and tibiae, regular puncture rows of the elytra and slightly convex elytral intervals, and the aedeagus near the apex with a narrow protrusion of the lateral side directed toward the aedeagus base.