by Patricia Robertson
Bees are flying flowers, says Gord Hutchings.
A bee expert and passionate advocate who’s been studying bees for over 25 years, Hutchings spent three weeks in the Yukon this summer to learn more about Yukon native bees.
Calling them flying flowers is Hutchings’ way of describing how bees evolved with flowering plants. “All bees have different tongue lengths that have evolved to reach certain depths of flowers,” he explains.
That’s because pollinating – not making honey – is the major purpose of bees. Scientists estimate that close to 80 per cent of flowering plants are dependent on pollinators – including wasps, flies, and moths – to help transfer their pollen.
Bees, however, are considered the most important pollinators, with roughly 800 species in Canada. That’s because each species tends to specialize in particular flowers, making them the most effective agent at transferring pollen to flowers within the same species.
The number in the Yukon isn’t yet known, but Alaska has somewhere around 35 to 40 bee species.
Though people are most familiar with the hive-dwelling honey bee – a species native to Eurasia and Africa – approximately 70 per cent of native bees in Canada are solitary ground-nesters.
The exception is the bumble bee (in the same family as the honey bee), which is the only true eusocial, or hive, bee in North America. Hutchings estimates there might be 12 to 15 bumble bee species in the Yukon.
Developed commercially as pollinators, bumble bees build one nest or hive per year, usually underground. “They like putrid, old, raunchy nests from mice,” says Hutchings, though any small mammal burrow or bird’s nest will do.
At the end of the season all the bumble bees die off except the queens, which will overwinter and then lay the eggs for the start of a new hive the following spring.
North American honey bees are facing what has been termed “colony collapse disorder,” an absence of adult bees in a hive where the queen, larvae, and honey are still present.
The main threat to the native bees of Canada, however, including the bumble bee, is habitat loss and fragmentation, as well as the use of pesticides and insecticides.
That’s why it’s important to learn to see a landscape from a “bee’s-eye” point of view in order to encourage the presence of bees.
“Weeds are wildflowers, and everything you see that you consider a weed appeals to bees,” Hutchings says, including such Yukon “weeds” as Canada and northern goldenrod, yarrow, and dandelion.
Although native plants are visually linked to whatever is pollinating them, flowers don’t rely solely on colour to attract bees and other pollinators.
“They also have patterns on the petals that we can’t see. Those patterns are like airstrip landing arrows that point to where the nectaries are. The flowers want to draw the bee to the nectar because as the bees go in they’re getting pollen brushed all over them.”
Adult bees may only live three or four weeks, overlapping with a different group of bees who specialize on another group of flowers. That’s why, says Hutchings, you want a different succession of foraging flowers to keep bees in your garden.
Bees are absolutely fixated on white, yellow, and blue. Because their vision picks up ultraviolet light differently from the human eye, white is actually a blue to them, while they see red as black. Some bees shift their colour fixation as they go through the season.
Hutchings has taken advantage of that fact to set out bee traps in the Whitehorse community garden. He uses yellow and white plastic picnic bowls filled with water, with a drop of dishwashing detergent added that allows the surface tension to be broken as soon as the insect touches it.
Hutchings wants to develop a baseline of bee species for the Yukon so that he can determine whether future climate change is altering the picture.
Has sweet clover – an invasive plant – brought in new species of bees? “That’s what I want to find out. I’d like to get gardening groups to put out some traps, even in parking lots that have cracks where weeds are coming up. It’s really easy to do. All you have to do is set the traps out, collect everything, and then send it down to me.”
In the meantime, Yukoners can take steps to make their own gardens bee-friendly.
Besides limiting the use of chemical pesticides, minimize your use of weed barriers such as black plastic or landscape fabric. Bees can’t tear through these barriers to reach the soil surface. Use newspapers instead, which biodegrade over time.
Cut back on the mulch, which discourages ground-nesting bees. Leave some sunny areas free of vegetation, where bees can find loose, sandy soil for nesting. Leave some leaf litter in the yard as well (bees will use it to camouflage the nest entrance). Don’t mow your lawn as often, and leave some weeds for the bees – bumble bees in particular love clover.
Finally, plant a variety of flowers that bloom from early spring to late fall. Bees need pollen and nectar to live, and if they can’t find flowers in your yard they’ll move elsewhere.
For more information on native bees and their care, including the use of bee “condos” (artificial nests), visit Hutchings’ comprehensive website at http://sites.google.com/site/hutchingsbeeservice/home.
This column is co-ordinated by the Northern Research Institute at Yukon College with major financial support from Environment Yukon and Yukon College. The articles are archived at www.taiga.net/yourYukon.