Sunday, April 4, 2010
The Common Eastern Bumblebee - Impatient for Domination
The first person I spoke to about bumblebees told me that whatever I might see, it would probably be Bombus impatiens, The Common Eastern (or Impatient) Bumblebee (CEB). That seemed hopeful. Gosh, it shouldn't be any trouble at all to know what species I was observing.
Turns out things are not quite so simple as all that. There are actually as many as 25 species of bumblebees occurring in eastern North America. You can never be certain of the species you have unless you become familiar with the identifying features of each of them.
But my informant was certainly right about the pervasive presence of the Common Eastern Bumblebee. The dominant nature of this species in eastern bumblebee communities has been reinforced once again in collections made during 2009 by the USGS Native Bee Inventory and Monitoring Lab .
The data made available by bee biologist, Sam Droege, show that of almost 600 specimens collected in 10 eastern states plus the District of Columbia, 65% of the total were the CEB. In those states represented by more than a handful of specimens, Bombus impatiens constituted no less than 64% and in one instance as much as 77% of the total. This species is certainly the most commonly encountered in the east.
Fortunately the CEB is relatively easy to identify too, at least for females, the queens and workers. They are characterized by yellow pile that covers most of the upper surface of the thorax, often with a black spot in the middle. And they have just a single band of yellow pile across the upper surface of the first visible abdominal segment. The rest of the abdomen is covered with black, furry pile. Unlike many other bumblebee species, there seem to be few different color forms or morphs to confuse the issue.
All in all, a most convenient species on which to begin biological observations - common and easily identified. So be on the lookout this summer for the Common Eastern Bumblebee. It will likely be the first one you see.
[Photo by D. Barr]