Bumble bees (Bombus) are important pollinators of crops and native plants. In North America
there are approximately 50 species of bumble bees that inhabit nearly every
terrestrial ecosystem on the continent. Bumble bees are social and
single queens form colonies in the Spring that grow throughout the year
until the colony matures in the Autumn (Figure 1). Colonies of some species can reach over 1000 individual bees living
and working together. The colony dies in the Fall of the year when
newly emerged queens and males leave the colony in search of mates and
Bombus come in a variety of colors and sizes. Many species look
similar due to mimicry complexes that form in geographic regions; but usually
the bees are fuzzy and have some combination of black, yellow, orange,
white, or red bands on their thorax and abdomen (Figures 2-5). Bombus seen early in the Spring are typically large queens searching
for nesting sites, whereas some species produce workers that are smaller
than a honey bee.
Bombus research at PIRU is concentrated in two areas:
- Developing species that are distributed in the Western U.S. for commercial
- Conserving wild bumble bee populations
We raise nests of bombus in the laboratory (Figures 6-7) to test the potential for different species to use in greenhouses (primarily as tomato pollinators - Figure 8).
Our conservation work focuses mainly on Bombus occidentalis, the Western Bumble Bee, which was historically widespread, but is now
found only in a portion of its historic range. We are currently documenting
the extent of the species range contraction and investigating potential
causes of the declines. See our postcard.
(Download Postcard in PDF format)
Lee Solter, Leah Lewis, James P. Strange, Mike Juhl