Integrative revision of the Caryocolum schleichi species group – a striking example of a temporally changing species concept (Lepidoptera, Gelechiidae)

Abstract

The taxonomy of the Palaearctic Caryocolum schleichi species group is revised, leading to a largely new species concept. Initially described as four different species (C. schleichi, C. arenariella, C. dianthella, C. improvisella), these taxa were later considered as subspecies. Recently the taxon C. arenariella was re-instated to species level without, however, revision of the remaining three subspecies. Analysis of DNA barcodes of the mtCOI (Cytochrome c Oxidase 1) gene of all four validly described taxa showed an unexpected pattern of genetic diversity. Careful re-examination of morphological traits, particularly male and female genitalia, fully supported this pattern, leading to the re-instatement of C. dianthella sp. rev. and C. improvisella sp. rev. as valid species and the description of three new species, all of them occurring in the Alps: C. messneri sp. nov. (Italy, Slovenia, Bulgaria, Greece), C. lamai sp. nov. (Italy, France) and C. habeleri sp. nov. (France, Switzerland, Germany). All species are described in detail and the adults and genitalia of both sexes are illustrated.