By Kimiora Ward
Widespread attention to pollinator declines has motivated land managers, farmers, and gardeners to plant wildflowers for pollinator habitat at large and small scales, but the question always arises - which native plant species give us the biggest bang for our buck? IAE's new Southwest Branch Restoration Program Coordinator Kimiora Ward recently contributed to research asking just that question. Native wildflowers can be expensive to establish, so it is important to know which species provide the greatest benefits to pollinators. Additionally, many farmers and other landowners worry that introducing native plants into their landscapes may bring additional costs in the form of pest insects that are attracted.
In a two year study set in the agricultural landscape of California’s Central Valley, the research team in the UC Davis Entomology Department measured insect use of 42 native California wildflower species to identify plants that support honey bees, native bees and other beneficial insects without supporting potential pests. While some species attracted pests as well as beneficial insects, others drew pollinators without this added liability. For example, phacelias (genus Phacelia) are well known for their attractiveness to bees, but the early-blooming Great Valley phacelia (Phacelia ciliata, see above photo) drew many fewer pests than California phacelia (P. californica) or tansy-leaf phacelia (P. tanacetifolia). When choosing plant species for supporting pollinators, it would be wise to consider not only bloom time and cost, but also attractiveness to both beneficial insects and pests. We are excited at IAE SW to build on this work and consider benefits to bees in our restoration and native plant materials programs.
See the abstract of this research paper at https://besjournals.onlinelibrary.wiley.com/doi/full/10.1111/1365-2664.13304 .