Mitochondrial DNA phylogenetic analysis of the genusLaparocerus(Coleoptera, Curculionidae, Entiminae). I. The Madeiran clade

Abstract

Laparocerus are plant‐chewing flightless weevils distributed on oceanic islands in Macaronesia, with a single species in Morocco. The genus has a complicated taxonomic history with several subgenera described. To assist in a taxonomical revision of the group, a molecular study was undertaken. In this first contribution, the species from the Azores and Madeira archipelagos are studied together with representatives of subgenera from the Canary Islands and the single known continental species (46 OTUs). Phylogenetic analyses are based on sequence data from mitochondrial cytochrome oxidase II (COII) and the ribosomal 16S ribosomal RNA (16S rRNA) genes (combined data set 1023 bp), with additional data from the nuclear elongation factor 1α (EF‐1α) for some selected species. Maximum likelihood (ML) and Bayesian analyses show that all Madeiran species are monophyletic and form a monophyletic group with the Afro‐Canarian samples. Species of the genus Lichenophagus appear within the Madeiran and Canarian Laparocerus clades, but separated in accordance with their respective island origin. Thus, Lichenophagus is here restricted to Madeiran species and proposed as subgenus (status novo) of Laparocerus. Conversely, the Laparocerus subgenus Drouetius from the Azores is revealed to be a separate and distant outgroup, in agreement with its morphological distinctiveness, deserving an independent genus status. Internal relationships within the Madeiran clade are discussed and compared with morphologically defined species groups. The Madeiran monotypic subgenus Cyphoscelis is not supported by the genetic data and synonymized (nov. syn.) with Laparocerus. Subgenera Laparocerus and Atlantis prove to be polyphyletic. Consequently a restriction to monophyletic and morphologically congruent clades is proposed. A cryptic species vicariant of Laparocerus morio was detected and recognized as L. chaoensis, status novo. Other cases of discrepancy between the genetic results and the traditional taxonomy are discussed in detail in the light of mitochondrial introgression, incomplete lineage sorting or poor taxonomy hypotheses.

New taxa of <i>Laparocerus</i> Schönherr, 1834 from Madeira and Porto Santo, with a key to the species of the Madeiran archipelago (Coleoptera, Curculionidae, Entiminae)

“…In order to better support the systematic decisions, the present morphological study is here combined with the results of the molecular analysis of Machado et al (2008), where mitochondrial DNA markers (fragments of cytochrome oxydase subunit II and of ribosomal 16S subunit) were selected as they are standard markers used in many phylogenetic studies (Caterino et al, 2000). Figure 1 shows the Madeiran clade of Laparocerus according to the Bayesian 50% majority-rule consensus tree obtained from the analysis of mitochondrial cytochrome oxidase II and ribosomal 16S rRNA gene sequence data (a combined dataset of 1023 bp) by Machado et al (2008, fig.1).…”

“…Figure 1 shows the Madeiran clade of Laparocerus according to the Bayesian 50% majority-rule consensus tree obtained from the analysis of mitochondrial cytochrome oxidase II and ribosomal 16S rRNA gene sequence data (a combined dataset of 1023 bp) by Machado et al (2008, fig.1). The phylogenetic tree has been simplified by removing the Bayesian support values and most Canarian, Azorean and some redundant Madeiran terminals.…”

“…Their Genbank accession numbers are FJ495251 (COII) + FJ495254 (16S rRNA), FJ495252 (COII) + FJ595255 (16S rRNA), and FJ495253 (COII) + FJ495256 (16S rRNA), respectively. Methodology followed was the same of Machado et al (2008). Pair-wise distances of mtDNA COII shown in Table 1 where calculated with MEGA.…”

“…A study of the type material of all species names ascribed to the genus yielded 24 valid species for the Madeiran archipelago (Machado, 2006). Preliminary results from a molecular analysis (Machado et al, 2008) suggest that the Madeiran Laparocerus species form a monophyletic group but also that Lichenophagus fritillus Wollaston, 1854 from Porto Santo clusters within the Laparocerus clade. Consequently, Lichenophagus was restricted to Madeiran archipelago species and relegated in status to a subgenus of Laparocerus.…”

“…Furthermore, Cyphoscelis Wollaston, 1854 was synonymised with the subgenus Laparocerus Schönherr, 1834. A few other changes in the systematics of the genus Laparocerus were suggested in Machado et al (2008) but not implemented.…”