The species of Timarcha Samouelle, 1819 described by Linnaeus (Coleoptera, Chrysomelidae)

Linnaeus described five species presently included in the genus Timarcha: Chrysomela goettingensis, Tenebrio caeruleus, Tenebrio laevigatus, Tenebrio latipes, and Tenebrio rugosus. After a study of the relevant material, the identity of these species has been established. The following synonyms are proposed or confirmed: Timarcha goettingensis (Linnaeus, 1758) = T. latipes (Linnaeus, 1767), syn. nov.; Timarcha caerulea (Linnaeus, 1758), comb. nov. = T. balearica Gory, 1833, syn. nov. = T. balearica Perez Arcas, 1865, syn. nov.; Timarcha rugosa (Linnaeus, 1767) = T. scabra (Olivier, 1807), syn. conf. = T. generosa Erichson, 1841, syn. conf.; Timarcha laevigata (Linnaeus, 1767) = T. tenebricosa (Fabricius, 1775), syn. conf.. The type of Tenebrio caeruleus is a Chrysomelidae currently belonging to genus Timarcha and therefore can no longer be considered a Tenebrionidae (Helops caeruleus) nor the type species of genus Helops. For the sake of nomenclatural stability, an application to the International Commission on Zoological Nomenclature to change the relative precedence of Timarcha caerulea and retain usage of T. balearica will be made. An application to change the relative precedence of Timarcha laevigata has been submitted, which would lead to the conservation of usage of T. tenebricosa as valid. Lectotypes are designated for Chrysomela goettingensis, Tenebrio latipes, Tenebrio caeruleus, Timarcha balearica Gory, T. balearica Perez Arcas, Tenebrio rugosus, Chrysomela scabra, Timarcha generosa, Tenebrio laevigatus, and Chrysomela tenebricosa. For each of the valid species the diagnosis, distribution, and host-plant data are reported.