What can I do to protect pollinators?
Floral richness is a good start. Different flower colors, different families of plants (different flower shapes and structures), and different flowering times increase the likelihood that all local native bees and flies will find something tasty when they emerge as adults. Try to have something flowering from March to early September. Don’t avoid using non-native plant species in the garden (as long as they are not invasive): most of our islands’ wild pollinators have broad tastes, and very few plants native to the islands flower after mid-July. But be sure to include some composites and umbels for small bees and hover-flies, and avoid a lot of reds that insects cannot see. Check ornamental flower varieties to see if bees visit them! Many lovely garden flowers produce little nectar or pollen–characteristics of little interest to flower breeders.
Maintaining a pollinator-friendly landscape involves more than planting flowers. Native bees and hover flies need reproductive habitat as well as food: for bees this means safe places to build nests; for flies, undisturbed places to lay eggs near larval food. When they “clean up” their property, people tend to eliminate bee-nesting habitat unwittingly.
A landscape must be varied and complex to be broadly pollinator friendly. It should include some brushy, sandy patches, as well as patches of deep leaf litter, and some old snags and logs. Leaving cut second-year berry canes standing, a pile of mossy rocks, and damp spots where there is soft mud, will all help attract bees. Bee habitat should not be raked, driven over or walked on; and of course, no pesticides, herbicides, moss control products, or spray fertilizers (which contain surfactants as emulsifiers that can be toxic to insects): anything that gets on pollen will accumulate in visiting bees and in their nests.
Eupeodes volucris (male), Iceberg Point, Lopez Island
Salish Sea landscapes are naturally soggy in spring, with countless seasonal puddles that feed hover-fly larvae; but producing more than a single generation of these useful flies each year depends on larger year-round marshes. Draining wetlands and digging out ponds to make them deeper reduces hover-fly habitat. Modest water features in a garden, such as a wet rockery with mosses and flowers, a small frog or turtle pool, even a neglected bucket with a little water, can be enough to ensure that Eristalini thrive. Syrphini live on aphid infestations, so efforts to eliminate aphids are also likely to kill hover-fly larvae. We recommend inspecting aphid masses for larval flies, and applying the “squish” method, if there are no fly larvae to do the job for you. To attract more of
these little-appreciated pollinators, include yellow composites (Asteraceae) and fragrant white umbels (Apiaceae) in vegetable beds and flower borders. Hover-flies will visit the flowers, and then check the garden for aphids!