New beetle, named in honour of Nova Scotia, found on Sable Island

By Christopher Majka, staff member and research associate with the Nova Scotia Museum. April 2006

A new species of beetle, hitherto unknown to science, has been discovered and named in honour of Nova Scotia – one of the few places where it is known to occur. The beetle called, Atheta novaescotiae, was formally described by myself and colleagues Jan Klimaszewski and David Langor of the Canadian Forest Service. The results were published in an article in the international journal, Entomological Science.

It’s an exciting discovery for several reasons. So far we’ve only found the beetle in Nova Scotia, Newfoundland, and on the French island of Sainte-Pierre et Miquelon and one of the areas where it is very abundant is Sable Island. This raises interesting questions about its origins and how it came to occupy this region.

We theorize that it survived the last glacial period on George’s Bank – which was not covered by glaciers – and it spread to Sable Island, the mainland of Nova Scotia, and Newfoundland, along the network of islands which existed along the continental shelf for several thousand years after the glaciers retreated. Therefore its presence on Sable Island may be a record of this pattern of colonization of Nova Scotia by plants and animals after the last glacial epoch.

Atheta novaescotiae is a “rove beetle” a member of the unusual looking family, the Staphylinidae, which are the most diverse, taxonomically complicated, and poorly understood of all beetles. It also occupies an unusual habitat: shoreline beach drift. It is found at the upper edge of the littoral zone where driftwood, seaweed, dead fish, seabirds, and other materials are deposited by the tides where it and other animals feed on and help decompose such flotsam. This distinctively maritime environment is also potentially vulnerable to disturbance since in many areas there are competing uses for beaches and shorelines.

My colleague Zoe Lucas, another research associate of the Nova Scotia Museum who participated in the discovery, and I have been studying the beetle fauna of Sable Island for the past two years. Atheta novaescotiae is one of approximately 150 species of beetles which are now known to occur on the island. The Sable Island environment is a unique one and several endemic plants, insects, and a sponge have been discovered on Sable Island. These are species which are found nowhere on earth underscoring the island’s importance as an ecological and evolutionary “laboratory.” Atheta novaescotiae, has also been found on the mainland of Nova Scotia in Glace Bay and on Brier Island, and around the coast of Newfoundland in Port aux Basques, Burgeo, Fogo, Stephenville, Gander, Cow Head, and Kitty’s Brook.

The discovery also has an evolutionary dimension. Initially researcher Jan Klimaszewski, who is a taxonomic expert studying the rove beetle family, believed that the beetle was a member of another group -- the genus Tarphiota found only on the Pacific coast -- since it bears a great resemblance to these beetles which also live on the shoreline. Only after very detailed anatomical examinations did it become clear that it is, in fact, a member of the genus Atheta. We believe the resemblance is due to a process called “convergent evolution” in which different animals living in similar environmental circumstances can come to have a similar, superficial appearance.

The discovery also has historical interest and significance. The first specimens of Atheta novaescotiae were collected in 1949 by the great Swedish zoologist, Carl Lindroth, formerly of the Zoological Institute at the University of Lund in Sweden, when he was engaged in his pioneering study of the ground beetles of Newfoundland. Lindroth, who also visited Nova Scotia and conducted research here, achieved prominence as one of the foremost scientists studying zoogeography. He developed many key ideas regarding the trans-Atlantic dispersal of flora and fauna, and the role humans have played in introducing European plants and animals to North America. Later, in 1966-67 an important Canadian entomologist, Henry Howden, then with the Canadian Museum of Natural Sciences, first collected the beetles on Sable Island as part of the first invertebrate survey done of the island.

Neither researcher knew at the time what these beetles were and it is only now, over a half century later, that we have been able to solve the puzzle. Therefore the discovery and description of Atheta novaescotiae is also a tribute to the work of these pioneer zoologists in helping to understand the fauna of this region.

These historically significant specimens join more recent ones collected by Zoe Lucas, Jeffrey Ogden of the Nova Scotia Department of Natural Resources, and students of David McCorquodale at Cape Breton University, all of whom assisted in the project. This study is one of a number of research projects we, in collaboration with researchers in Nova Scotia and abroad, are leading in order to develop an understanding of the systematics, biodiversity, distribution, and ecology of Nova Scotia beetles. Beetles are possibly the largest component of province’s fauna and until recently very little has been known about them in Nova Scotia.

For further information contact Christopher Majka: (902) 425-3725, or c.majka@ns.sympatico.ca

Klimaszeski, J., Majka, C.G., & Langor, D. (2006) Review of the North American Tarphiota Casey, with a description of a new seashore-inhabiting species Atheta species exhibiting convergent characteristics (Coleoptera: Staphylinidae: Aleocharinae). Entomological Science 9: 67–78.

A copy is available for download at: http://www.chebucto.ns.ca/Environment/NHR/PDF/Tarphiota.pdf

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