A revision of Meladema diving beetles (Coleoptera, Dytiscidae), with the description of a new species from the central Mediterranean based on molecules and morphology

By

Bilton, David T.
Ribera, Ignacio

Type

Article

Date of Publication

2017

Original Publication

ZooKeys

Volume

702

Pages

45-112

Subjects

Biodiversity , Biogeography , cryptic species , Entomology , freshwater , integrative taxonomy , systematics

Contributed by

Pensoft Publishers

Language

English

Published by

Sofia, Bulgaria Pensoft Publishers

Identifiers

DOI: https://doi.org/10.3897/zookeys.702.14787

 

Abstract

Meladema Laporte, 1835 are relatively large, stream-dwelling diving beetles, distributed widely in the Western Palaearctic, from the Atlantic Islands to Turkey, and from southern France and the Balkans to the central Sahara. In addition to the three previously recognised taxa (M. coriacea Laporte, 1835, M. imbricata (Wollaston, 1871) and M. lanio (Fabricius, 1775)) we describe a new, cryptic, species from the central Mediterranean area, which can be distinguished from M. coriacea on both DNA sequence data and morphology, and provide a key to known species of the genus. Based on the study of genotyped material, both recent and archival, as well as the examination of a large number of museum specimens, we show that M. lepidoptera sp. n. occurs to the apparent exclusion of M. coriacea on Corsica, Sardinia and islands of the Tuscan Archipelago, but that both taxa are found in peninsular Italy, where they may occasionally hybridize. In the absence of the original type series, we designate a neotype for M. coriacea, and take the opportunity to designate a lectotype for M. lanio. Morphological variation in Meladema species is discussed, including that seen in known and presumed hybrids. Our study highlights the incomplete state of knowledge of Mediterranean biodiversity, even in relatively large, supposedly well-studied taxa.