Allozyme and RAPD analysis were performed to clarify taxonomic relationships within the Meligethes viridescens complex (Coleoptera, Nitidulidae, Meligethinae). Five populations from Central Italy belonging to three species: M. viridescens, M. czwalinai, and a new undescribed species (M, sp. cfr. viridescens), and one population of the morphologically well-differentiated M. aeneus were analysed. The degree of observed genetic differentiation supports separation at the specific rank of M. viridescens, M, czwalinai, and M. sp. cfr. viridescens. The species' ecology and morphological observations based on scanning electron microscopy also supports such a taxonomic separation. The M13 RAPD primer is a diagnostic marker for distinguishing the four species. Estimates of divergence times calculated from allozymic genetic distance data suggest that the pattern of differentiation observed may be related to the palaeoclimatic changes during the Plio/Pleistocene ice cycles in southern Europe. (C) 1999 Published by Elsevier Science Ltd. All rights reserved.