It has been fourteen years since the publication of the sixth volume of the Catalogue of Palaearctic Coleoptera, which contained the entire superfamily Chrysomeloidea. Since then, numerous taxa have been described or changed status, and many genera have undergone modern revisions. There is also a substantial number of new or overlooked data on distribution. Last but not least many mistakes were found that needed to be corrected. Due to the enormous size of the entire superfamily, the sixth volume was split into two parts in the new series. The first part containing Cerambycidae sensu lato was published in 2020. In this part, the remaining families of Chrysomeloidea are treated, following in this respect traditional classification, but it must be stated that Orsodacnidae and Megalopodidae have recently been found to belong to the cerambycoid clade, robustly supported by adult and larval morphology as well as molecular data. However, since they were not covered in the first part of Volume Six, they are included here.

This part somewhat deviates from all hitherto published volumes of the series as we made some additions. The general concept of the catalogue is still the same, but we also decided to include all infrasubspecific names, i.e. all names ever published within Palaearctic Orsodacnidae, Megalopodidae, and Chrysomelidae are listed (except for nomina nuda). Sometimes it is clear that a name is an infrasubspecific entity by definition (e.g. aberrations). On the other hand, the infrasubspecific status of many names is disputable, which might cause some difficulties in the future, i.e. in homonymies with new taxa. Also, even when the name used is an infrasubspecific entity, there is a distributional record behind it that is still valid. Thus, we decided that all such names should be included to give the reader possibility to find out the present status of each name and to which taxon it refers, as they are not always associated with the original maternal taxon to which they were assigned.

We also put a special emphasis on the distributional data as the previous edition contained many records that were never published, or erroneous or simply repeated from other works despite obvious biogeographic discrepancies. Therefore, the present Edition is mainly based on published records and many suspicious or otherwise problematic distribution records are commented on, to give the reader the most up to date and accurate overview. For this reason, we included new faunistic records in the New Acts chapter.

Finally, the major change is that we decided to include the publication date for each reference cited as accurately as possible and provided the sources of such information. This is an essential basis for the principles of the zoological nomenclature to establish correct synonymies and confirm validity of taxa, and we believe this will be beneficial to all insect taxonomists, as many works contain multiple groups, or at least the cited source provides potentially useful evidence for other volumes/issues within the series. We are aware that many of the dates we give might be specified or changed in the future, because research on this topic is going on and we certainly have overlooked some of the sources. However, we would be satisfied if the data we present were adopted as a basis for further research.

The present part of the Catalogue covers three families, namely Megalopodidae, Orsodacnidae, and Chrysomelidae. The last is the most species rich, and is divided into 11 subfamilies. In total this part contains 596 genera, 165 subgenera, 9398 species and subspecies, and 100 nomina dubia. Following new nomenclatural acts are introduced: one new tribe, one new subtribe, one new species, two new subspecies, ten new substitute names, 37 new combinations, 149 new synonymies, ten nomina protecta, and nine nomina oblita. For the purpose of the stability of nomenclature 15 lectotypes are herein designated. In addition, new distributional data for 351 species are recorded.