Worcestershire Record No. 27 November 2009 p. 22

Geoff Trevis

There is growing evidence of a change in bumblebee behaviour which is being driven primarily by climate change. Bumblebees have the unusual ability to warm their flight muscles and thus they are well placed to take advantage of any slight increases in winter temperatures. Indeed, bumblebees may be found flying and foraging on winter flowering Ericas and other plants at temperatures close to freezing!

The buff-tailed bumblebee Bombus terrestris is of particular interest in that records from the far south of England indicate that it may be maintaining viable colonies throughout the winter thus having a head start in the spring. Normally, of course, only queens survive the winter by hibernating under ground or under bark, leaves or in other sheltered situations to emerge in the spring to found new colonies.

A national scheme is now underway to record bumblebees during the winter, especially B. terrestris which is recognised by having a black thorax and abdomen with two yellow bands, one on the front of the thorax and one on the abdomen and with a white to buff tail. Other bumblebees that might be seen are the red-tailed bumblebee Bombus lapidarius and the ginger coloured B. pascuorum. The only species likely to cause confusion is the white-tailed bumblebee B. lucorum whose workers are very similar to those of B. terrestris. However, B. lucorum is generally brighter in colour with a snow white tail undiluted by any buff hairs, even at the junction with the black of the rest of the abdomen. I would be very grateful to receive any records of these species either directly to me at geoff.trevis@btinternet.com or via the Worcestershire BRC. If you are in doubt about B. terrestris and B. lucorum simply record as buff/white tailed bumblebee. All records are important. Your help will be much appreciated.