To Help Save Bumble Bees, Plant These Flowers in Your Spring Garden
There are nearly 20,000 known bee species in the world, 4,000 of which are native to the U.S., according to the U.S. Geological Society. Bees pollinate roughly three-quarters of all fruits, nuts and vegetables grown across the country and one of every four bites of food can be credited to bee pollination. But bees are in major decline as nearly 40 percent of honey bees have declined in the last year, according to ABC News. Populations have dropped for a number of reasons, including parasites, pesticides and a lack of flowers on the landscape — all factors that highlight a need for understanding habitat needed to sustain and recover populations.
Working with the Entomological Society of America, scientists set out to determine which flowers bumble bees prefer in an effort to aid land managers seeking to restore critical habitat.
“It’s important to consider the availability of plants when determining what’s selected for by bees,” Jerry Cole, study author and biologist with the Institute for Bird Populations (IBP), said. “Often studies will use the proportion of captures on a plant species alone to determine which plants are most important to bees. Without comparison to how available those plants are, you might think a plant is preferentially selected by bees, when it is simply very abundant.”
To come to their conclusions, researchers captured more than a dozen different species of bumblebees on more than 100 different species of flowers in the Sierra Nevada region of California. Researchers recorded what species of flower each bee was captured on and then estimated the number of plants found in each plot. The findings suggest that different bumblebee species select specific flowers even when foraging across the same landscape.
“We discovered plants that were big winners for all bumble bee species but, just as importantly, plant species that were very important for only a single bumble bee species,” said Helen Loffland, a meadow species specialist with the Institute for Bird Populations. “This study allowed us to provide a concise, scientifically based list of important plant species to use in habitat restoration that will meet the needs of multiple bumble bee species and provide blooms across the entire annual lifecycle.”
The yellow-faced bumble bee (Bombus vosnesenskii) was most abundantly observed. The endangered insects preferred large-leaved lupine (Lupinus polyphyllus) and consistently chose the flowering plant even when others were available. Three of five bumblebee species were found to prefer A. urticifolia, a flowering plant in the mint family.
Some of other favorites? The fuzzy buzzing insects also preferred Oregon checker-mallow (Sidalcea oregana), Alpine mountainbalm (Monardella odoratissima), tall fringed bluebells (Mertensia ciliate) and cobwebby hedge nettle (Stachys albens).
It is important to note that bees likely don’t have natural preferences but instead choose flowers based on quality or quantity of nectar or pollen. People should interpret the results with caution because the researchers did not conclude whether plants were being used for pollen or nectar sources, CNN notes.
The U.S. Forest Service says that it is using the study results to identify areas where restoration efforts may make more ample bee habitat.
“This sort of knowledge can really increase the effectiveness of restoration for bumblebees in a way that is relatively easy and cost-effective to implement,” said Loffland, adding that the findings can be helpful to landowners who are restoring or managing areas that are habitat for native bees.