This excellent new research has just published! In a nutshell if we plant an area with wild flowers that area will yield 4 times as many bumble bees, so its some thing we can all do and get involved with.
The scientists used a combination of different approaches (habitat manipulation, land-use and habitat surveys, demographic and spatial modeling and molecular genetics) to come to a robust overview as to the effects of habitat quality (i.e. wildflower availability) on bumblebee survivability.
It was found availability of access to wildflowers could markedly increase bumblebee survivability, by up to four times compared to control, or having no wildflower access in an agricultural landscape.
The main things to take away from this study is that diversity of wildflowers is very important for all bees…most solitary bees are much more selective when it comes to pollen/nectar diet, so if certain species of wildflower disappear from the landscape, species will be lost.
Bumblebees are distinct from these other bees in that they have a much wider palate when it comes to pollen and nectar, they are polyphagous feeders in this respect feeding on many wildflower species, so the more available to them in otherwise poor quality habitats (such as agricultural land), the more their populations will respond, and their survivability will increase.
So this study in turn provides strong evidence for the importance and usefulness of habitat conservation and conservation measures.
The study emphasizes the importance of planting species that flower throughout the year over the spring/summer.
Sam Droege, a biologist who runs the U.S. Geological Survey’s Bee Inventory and Monitoring Lab (not involved with the study) had this to say:
“Bumblebees, whose pollen palette is very broad, benefit from retaining a wide range of native wild flowers in an environment,” says Droege. “Other bees are much more restricted in their diet, and loss of plant biodiversity simply eliminates some from the landscape completely.”