Assemblages of the Heteropterans and Weevils (Heteroptera; Coleoptera, Curculionidae) in the Petrophytic Steppe of the Barguzinskaya Depression, Buryatia

A motley grass steppe site with an area of 25 hectares was investigated on a slope of the right bedrock coast of the Ina River, a left tributary of the Barguzin River in Buryatia. An assemblage of the heteropterans in the area was found to consist of only 30, and that of the weevils, of 16 species. The host plant to weevil species ratio at this site near the northeastern boundary of the steppe zone is about 6 : 1, i.e., fourfold that in the plain part of Stavropol Territory close to the western boundary of the steppe zone in its most diverse although least preserved part. Two new wingless species of weevils with apparently very narrow ranges, probably restricted to the Barguzinskaya Depression, are described— Phyllobius ( Angarophyllobius ) sofronovorum Korotyaev, sp. n. and Stephanocleonus ( Stephanocleonus ) lysovi Korotyaev, sp. n.