Garden hospitality - Welcoming the pollinators (Part 1: "Who" are the pollinators?)
“We need to undo the damage we have done to make the world inhospitable for the very bees that make our planet liveable—and it is through our gardens that each of us can make a difference.”
The creation of a pollinator garden is an intentional act of hospitality. It challenges the notion that every “bug” in my yard is a threat, a misconception too often promoted by the gardening industry. Certainly some insects harm my plants. But, the vast majority of six-legged garden visitors are either benign or are providing significant benefits. In truth, a few creatures are not welcome in my garden but I am trying to change my default setting to hospitality, suspending my suspicions and extending a welcome to the backyard “bugs.” I hope they enjoy their visit and (perhaps) choose to make this garden their home.
This post follows my essay, “Making peace with the garden” (Feb 7 2020), in which I argue that our war on nature needs to end. I think a pollinator garden is an act of peacemaking and a constructive step in the long journey towards reconciliation. So to that end, in this post I would like to introduce the pollinators.
Bee on Garden cosmos (Cosmos bipinnatus), Victoria, BC.
“Who” are the pollinators and why are they so important?
Fawn lily (Erythronium oregonum), Victoria, BC.
In order to appreciate the work of pollinators it is helpful to remember that flower blossoms are essentially reproductive organs. The male flower parts produce pollen grains and surround the female structure which produces the eggs. You can see the yellow pollen coating the male anthers in this photo of a Fawn lily. Pollen grains contain sperm cells and need to be delivered to the tip of the female structure — preferably on a different flower of the same species in order to achieve cross-pollination. Although some plants are self-fertile and others, such as grasses, use wind to disperse their pollen, a very large number of plants depend on insects or other animals to transfer their pollen. For without pollination the egg can’t be fertilized and that means no seeds and no fruit (and, sad face).
When insects like bees visit flowers to harvest and feed on their pollen or nectar, some pollen is transported from one blossom to another. Since the grains of pollen hold a plant’s sperm cells, and since the eggs are hidden deep within female flower structures, the pollinator plays a key role in assisting plant reproduction.
In my garden on the southern tip of Vancouver Island, British Columbia the pollinators include many species of flies, bees, wasps, beetles, butterflies and moths. Hummingbirds and other animals assist some plants in pollen transfer but here I focus on insect pollinators, especially our native bees. Bees are the most efficient insect pollinators because they actively move from flower to flower feeding on nectar and gathering the pollen grains which they use to feed their offspring. And, bees are built to transport pollen. They often have specialized body and leg hairs that trap pollen grains, and some even have pollen baskets! A lot of pollen is also carried by bees unintentionally, caught in random body hairs and often stuck to their little faces.
It is the wild native bees, as opposed to the familiar honey bees, that are the primary focus of pollinator conservation. The European honey bee (Apis mellifera) is actually an introduced species to North America, and is perhaps best thought of as a “farm animal” ... like a chicken or a dairy cow. And, as someone has pointed out, when we speak of bird conservation we aren’t usually thinking about chickens!
This doesn’t mean we don’t care about honey bees. Apiculture (bee-keeping) is obviously a large and important piece of the agricultural sector in Canada. Canola, blueberry and tree fruit crops rely heavily on pollination by honey bee colonies and of course, we all love honey! We also know that honey bees have been hard hit in recent years. Severe winter die-offs and the collapse of honey bee colonies have been costly for bee-keepers. The causes are lethal combinations of poor nutrition, pesticides, climate change, parasites such as the varroa mite, and an assortment of diseases caused by viruses, bacteria and fungi. This is of enormous concern from an agricultural and economic point of view. And, it is of ecological concern because early evidence suggests our native bees are vulnerable to the same threats (See Rhodes).
Bumble bee on Woolly sunflower ( Eriophyllum lanatum ), Victoria, BC.
It’s not surprising that discussions about bees focus on the honey bee but it is unfortunate that our native bees are often overlooked. In fact, most people aren’t even aware of the abundance and diversity of native bees. Or, their ecological and agricultural importance. Here in British Columbia, Canada, 483 species of bees have been recorded! These bees are very diverse and include polyester bees, mining bees, sweat bees, leaf-cutter bees, mason bees, carpenter bees, honey bees, bumble bees, and even an oil-collecting bee (See Sheffield & Heron). While some of these bees are social, most wild bees in North America live solitary lives and most species nest in the ground. And, importantly, they are usually non-aggressive and rarely sting.
It is interesting what you discover once you start looking; the diversity of pollinators in my own gardens is really quite remarkable. I’ve spotted numerous species of bumble bees, mason bees, leaf-cutter bees, ground nesting bees, cuckoo bees, green sweat bees, and wasps and flies of all sorts! I am pretty sure that is just a start. I am trying to photograph and identify them but this is a work in progress.
Let me share what I have learned about one of the bees in my garden. The first bee pictured in the slideshow (above) is a cuckoo bee – Genus Nomada. With its narrow waist and yellow markings it looks a little like a wasp. Cuckoo bees visit flowers for nectar but unlike most bees they do not collect pollen and they don’t build their own nests. Cuckoo bees are cleptoparasites (“thieving parasites”), laying their eggs in the nests of other species and benefiting from the hard work of others. The Nomada female enters the burrow of a ground nesting bee and lays her egg alongside the host bee’s egg. When the Nomada egg hatches, the larva uses its large, sickle shaped mouthparts to destroy the host’s egg. Having killed off its competition, the Nomada larva merrily consumes the pollen stash gathered by the host bee to feed its own young, and in the process earns the dubious label, “cleptoparasite” (See Lee-Mäder). Interesting! Until this summer I had no idea.
All of which raises a few question for me: What else is happening in my garden that I am oblivious to? Do all gardens have an abundance of interesting insects? And, what can I do to make my garden more attractive to pollinators and other beneficial insects?
That is where I will pause for now. Future posts will develop this idea of garden hospitality, outlining the threats to pollinating insects and exploring practical steps for designing and creating a pollinator garden. ‘Till then.
Burl
RESOURCES:
There are many excellent resources that support pollinator conservation. Here are two excellent books, two articles and two websites to get you started:
Lee-Mäder, E., & Xerces Society. (2011). Attracting native pollinators: Protecting North America's bees and butterflies : the Xerces Society guide: Storey Publishing.
Weidenhammer, L. (2016). Victory gardens for bees: A DIY guide to saving the bees: Douglas & McIntyre.
Rhodes, C. J. (June 01, 2018). Pollinator Decline – An Ecological Calamity in the Making? Science Progress, 101, 2, 121-160. https://journals.sagepub.com/doi/pdf/10.3184/003685018X15202512854527
Sheffield, Cory S. & Heron, Jennifer M.. The bees of British Columbia (Hymenoptera: Apoidea, Apiformes). Journal of the Entomological Society of British Columbia, v. 115, p. 44-85, Mar. 2019. https://journal.entsocbc.ca/index.php/journal/article/view/1001.
Island Pollinator Initiative https://islandpollinatorinitiative.ca/
Pollinator Partnership Canada https://pollinatorpartnership.ca/en/