Phylogenetic analysis of the genusLaparocerus, with comments on colonisation and diversification in Macaronesia (Coleoptera, Curculionidae, Entiminae).
The flightless Entiminae weevil genusLaparocerusis the species-richest genus, with 237 species and subspecies, inhabiting Macaronesia (Madeira archipelago, Selvagens, Canary Islands) and the continental 'Macaronesian enclave' in Morocco (one single polytypic species). This is the second contribution to gain insight of the genus and assist in its systematic revision with a mitochondrial phylogenetic analysis. It centres on the Canarian clade, adding the 12S rRNA gene to the combined set of COII and 16S rRNA used in our first contribution on the Madeiran clade (here re-analysed). The nuclear 28S rRNA was also used to produce an additional 4-gene tree to check coherency with the 3-gene tree. A total of 225 taxa (95%) has been sequenced, mostly one individual per taxa. Plausible explanations for incoherent data (mitochondrial introgressions, admixture, incomplete lineage sorting, etc.) are discussed for each of the monophyletic subclades that are coincident with established subgenera, or are restructured or newly described. The overall mean genetic divergence (p-distance) among species is 8.2%; the mean divergence within groups (subgenera) ranks from 2.9 to 7.0% (average 4.6%), and between groups, from 5.4% to 12.0% (average 9.2%). A trustful radiation event within a young island (1.72 Ma) was used to calibrate and produce a chronogram using the software RelTime. These results confirm the monophyly of both the Madeiran (36 species and subspecies) and the Canarian (196 species and subspecies) clades, which originated ca. 11.2 Ma ago, and started to radiate in their respective archipelagos ca. 8.5 and 7.7 Ma ago. The Madeiran clade seems to have begun in Porto Santo, and from there it jumped to the Desertas and to Madeira, with additional radiations. The Canarian clade shows a sequential star-shape radiation process generating subclades with a clear shift from East to West in coherence with the decreasing age of the islands.Laparocerus garretaifrom the Selvagens belongs to a Canarian subclade, andLaparocerus susicusfrom Morocco does not represent the ancestral continental lineage, but a back-colonisation from the Canaries to Africa. Dispersal processes, colonisation patterns, and ecological remarks are amply discussed. Diversification has been adaptive as well as non-adaptive, and the role of 'geological turbulence' is highlighted as one of the principal drivers of intra-island allopatric speciation. Based on the phylogenetic results, morphological features and distribution, five new monophyletic subgenera are described:Aridotroxsubg. n.,Belicariussubg. n.,Bencomiussubg. n.,Canariotroxsubg. n., andPurpuraniussubg. n., totalling twenty subgenera inLaparocerus.
Chopin 1, 38208 La Laguna, Tenerife, Canary Islands, Spain.
Antonio
A
Machado
Chopin 1, 38208 La Laguna, Tenerife, Canary Islands, Spain; Instituto Universitario de Enfermedades Tropicales y Salud Pública de Canarias.
Eduardo
E
Rodríguez-Expósito
Chopin 1, 38208 La Laguna, Tenerife, Canary Islands, Spain; Instituto Universitario de Enfermedades Tropicales y Salud Pública de Canarias.
Mercedes
M
López
Instituto Universitario de Enfermedades Tropicales y Salud Pública de Canarias; Departamento de Bioquímica, Microbiología, Biología Celular y Genética. Universidad de La Laguna. Avda. Astrofisico Fco. Sánchez s/n 38207 La Laguna, Tenerife, Spain.
Mariano
M
Hernández
Back-colonisation; Bayesian inference; Canary Islands; Madeira; Moreiba Morocco; Selvagens Islands; dispersal; divergence rates; introgression; island evolution; mitochondrial DNA; new subgenera; phylogeny; speciation; weevils