A trio of beautiful beetles
February 1, 2012
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This fall I spent some time under the tutelage of some of Canada’s best-known entomologists at the Canadian National Collection of Insects, Arachnids and Nematodes, with the specific goal of confirming some of my identifications of Arctic ground beetles (Carabidae).
One researcher, Dr. Henri Goulet, currently works on sawflies (Hymenoptera) but he started his entomological career as a beetle guy. His insights and identification “tips” for my beetles were amazing. Dr. Goulet also knows a thing or two about capturing insects – not with traps, but with his camera. He’s compiled hundreds of photographs of Canadian ground beetles for the Canadian Biodiversity Information Facility.
During my first summer in Nunavut, I was fortunate to collect a good series of a ground beetle called Blethisa catenaria. It was formerly known by only 4 other specimens, all over 50 years old; I found just over 30 more.
One of the wonderful things my collection taught us about this species is that they come in several colours. You’ll recall that I wrote a post not long ago on the color variation in another Arctic beetle, Pterostichus (Stereocerus) haematopus. Blethisa catenaria provides another great example – except it is decidedly SHINIER. Says Dr. Goulet about the variation in B. catenaria: “Based on your specimens, the color forms are not discrete, but gradually shift from dark to either green or copper”. Cool!
Dr. Goulet was very excited to get some photographs of the different color morphs of B. catenaria, and just this week he completed his work on the images. With his permission, I’m sharing them with you now:
Blethisa catenaria ("brown") - Photo by: Henri Goulet
Blethisa catenaria ("dark") - Photo by: Henri Goulet
Blethisa catenaria ("copper") - Photo by: Henri Goulet