Wednesday, 25 July 2012

Systematics of South Pacific sap beetles

Carpophilus maculatus, Carpophilus cheesmani and Carpophilus oculatus
The species of Carpophilus of particular interest: dorsal habitus above, male parameres below.

Two and a half years ago, I completed my MSc looking at the sap beetles in the genus Carpophilus. In particular, I looked at the C. oculatus species complex from the South Pacific. The species was first described in 1864, before it settled into obscurity. It was only mentioned a few times in the literature until 1993, when Ron Dobson published the results of a study where he looked at a large series of the species. He described three subspecies, two of which were widespread and sympatric, while the third was confined to Vanuatu. Another species, C. maculatus is rather similar in appearance, to the extent that questions were being raised as to the validity of the taxon complex.

My task was to look at this group using molecular methods. In particular, I used three genes to investigate the relationships between these four taxa, and any other species of Carpophilus I could get my grubby hands on. I found that C. maculatus is indeed a distinct species from C. oculatus, and also found sufficient evidence to warrant raising the subspecies from Vanuatu to a full species. The other two subspecies, while being somewhat distinct, did not form entirely separate groups, which suggests that something interesting has happened in the genetic history of these taxa. It was a successful and enjoyable project, and I am proud to say that I completed my MSc with first class honours.

So far, so good. However, the currency of modern academia is peer-reviewed publications. The preparation of manuscripts is an arduous process, and over the past two years the one describing the aforementioned research has been languishing on various people's desks (mine, mainly). In the past month though, it been brought into the light of day and has been published in Molecular Phylogenetics and Evolution. Check it out! If you don't have access to it, feel free to email the author.

Brown SDJ, Armstrong KF, Cruickshank RH. 2012. Molecular phylogenetics of a South Pacific sap beetle species complex (Carpophilus spp., Coleoptera: Nitidulidae). Molecular Phylogenetics and Evolution, 64(3), 428–440

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