"In combination with earlier work showing that bumblebees have become rare in agricultural landscapes, our study suggests that farmers could promote these valuable pollinators by diversifying crop types and by planting cover crops and flowering hedgerows to enhance floral diversity," said Kremen.
Though it may seem obvious that pavement and ground nesting don't mix, Jha said that our understanding of the effects of pavement and urban growth on native bees has been largely anecdotal.
"Using genetic tools, we can now estimate the number of colonies in an area," said Jha, who began this work as a postdoctoral researcher at UC Berkeley. "This is helping us better understand how wild pollinators live and move across large, diverse landscapes."
Bumblebees nest in the ground, and each colony contains a queen and a force of workers. As with honeybees, all of the bumblebee workers are sisters who spend some of their time flying around searching for flowers from which to collect pollen and nectar to feed the larvae back in the hive.
Unlike honeybees, which are not native, bumblebees do not make harvestable honey. They do, however, provide important pollination services to plants.
"Bumblebees are among the most effective native pollinators," said Jha. "They are large and can carry a lot of pollen. They also vibrate or 'buzz' flowers with their bodies and thus are excellent at extracting pollen and moving it from plant to plant."
To study the bumblebees, Jha did not scour the landscape for nests in the ground, whic
|Contact: Shalene Jha|
University of Texas at Austin