A new genus and species of geometrid moths from Tadjikistan is described and its position in the taxonomic structure of the subfamily Larentiinae is analysed. The new genus is grouped, based on the parsimony analysis of 38 morphological characters, to coniferous-feeding genera of the tribe Cidariini as follows: (Thera (Pennithera (Protothera (Pljushtchia gen. n. Heterothera)))). Pljushtchia is characterised by the antennae, unipectinate in males and flat, serrate in females, by a reduced haustellum, the venation of wings and the structure of the genitalia. The Thera firmata species group is validated as a genus Protothera. The tribe Cidariini includes four groups of related genera and is most speciose in southeastern Asia.