surveying bumble bees in urban areas
- Hi, all-
I'm looking for some input. I have been asked to join a group of researchers studying insect diversity across an urban gradient. My role is to look at bumble bees.
Pan traps are being used for other insects, but I am not sure about using them for bumble bees. I am under the impression that bumble bees are less likely to land in pan traps than other bees, and Bombus diversity would be skewed. It seems like netting might be the way to go, but I am not sure how to standardize netting across urban areas.
Do you think that bringing the same blossoming plant around with me and netting bees visiting that plant would work? Is there some way to make pan traps more Bombus friendly?
Thanks for the advice
- Christine Urbanowicz
Graduate Student, UNC
- --- In email@example.com, "chrisu875" <cu@...> wrote:
>My own personal observation is that different species of bumblebees are often working different species of plants. And Bombus impatiens, in my experience, works the widest range of plants here in South Carolina. (It's also the only species that is still common around here.) B. pensylvanicus is much more restricted.
> Hi, all-
> I'm looking for some input. I have been asked to join a group of researchers studying insect diversity across an urban gradient. My role is to look at bumble bees.
> Do you think that bringing the same blossoming plant around with me and netting bees visiting that plant would work?
There is also the factor of tongue length and the depth of the corollas. Shorter toungued Bombus may not be able to work some flowers because of this.
Another factor is the species that are already being foraged may be different from one area to another. If you carry in a plant that they are already habituated to, they will tend to notice it faster than a new flower species.
All in all, I think carrying flower around, would tend to skew the results.
Better to learn the gamut of plant species that they do work in the region and teach yourself to be observant.
Just my opinion...I'm not an expert.
- I agree that catching the bees at the flowers is best. I prefer
catching them directly into containers right at the flowers rather
than catching them in nets and then transferring them to containers. I
use snack size reusable plastic tupperware type containers. Nets are
super handy if they are foraging in tall shrubs or trees, though.
I also agree that although they are generalists, not all bumble bees
visit the same flower species. A better way to standardize across the
gradient would be to standardize your search effort. Cover the same
area in the same amount of time. Floral resource density will vary
across your urban gradient, so get measures of that. Hopefully you'll
have the time and resources to sample enough sites so that this
variation can be dealt with.
Best of luck.