Larvae of Polia lamuta (Hertz, 1903) and P. conspicua sabmeana Mikkola, 1980 are described for the first time and larvae of five other European species of the genus, viz., P. serratilinea (Ochsenheimer, 1816), P. richardsoni (Curtis, 1834), P. bombycina (Hufnagel, 1766), P. tincta (Brahm, 1790) and P. nebulosa (Hufnagel, 1766), are redescribed. The hypopharyngeal complex, mandible and head of the species are figured. The phylogeny of the examined species of Polia is outlined on the basis of larval characters and the genus is divided into two subgenera: Polia s.str. and Chera Hübner, 1816. A key to the subgenera and species is presented, largely on basis of the larval mouthparts, chaetotaxy and ornamentation.