Help bring the bees back

ON THE GARDEN PATH by Carolyn Herriot

The honeybee Apis mellifera was brought to North America by European colonists in 1662 to pollinate their crops. Before European honeybees were imported to North America, generations of growers depended upon the 4,000+ species of native bees that lived there. In Canada, there are 800 species of native bees. These bees do not live in communal hives; they are solitary, dwelling in little caves in the ground or in bark crevices in trees where they raise their young.

Today, more than 25 percent of North America’s 2.4 million honeybee colonies have been lost to what has been named “colony collapse disorder.” The bees are stressed by mites, viruses, toxic pesticides, long-distance trucking and poor nutrition. Hundreds of acres of mono-cultured crops do not provide the diversity of food they need to stay healthy. This has farmers worried about how they are going to get their crops pollinated in future.

A bee box (with stackable trays) attracts solitary pollinating bees to the garden.

The answer is right in front of them: if we returned to the smaller-scale, diversified food production model of our forbears, one that protected habitat such as hedgerows and ponds for wildlife, we would not be concerned about the failures of ‘rent-a-bee’ services.

There are 20,000 species of bees in the world, which means there are thousands of bees we know little about. In Victoria, BC, where I live, there are 30 species of native bees, which live in wild places such as salmonberry thickets, dead trees, decaying logs, riverbanks and abandoned railway corridors. The closer they are to a city, the more native bees are under threat, due to loss of habitat.

Here in Victoria, my friend Rex Welland spent many years studying native bees as a result of his interest in heritage fruit trees. He noticed that apples typically produce 10 to 20 seeds, depending on the variety. When he noticed that seed numbers had dropped in his fruit, he became concerned that bee populations were being negatively affected by mite infestations. He decided to try attracting native species of bees to increase the rate of pollination.

Rex perfected a wooden bee box, with slotted trays that could be taken apart at the end of the season to clean pollen mites off the cocoons. Hatching unencumbered by mites enhances the adult bee’s survival rate. In no time, the native blue orchard mason bee Osmia lignaria had located and moved into Rex’s bee boxes. This non-aggressive solitary bee is a shiny, blue-black colour and slightly smaller than a honeybee, making it easily mistaken for a bluebottle fly. There are 35 different species of orchard mason bees in North America.

Plant these and 
bring the bees
Apple, cherry, plum
Blackberry & raspberry Rubus
Saskatoon berry Amelanchier alnifolia
Dandelion Taraxacum officinale
Mints Mentha
Marjoram Origanum
Nasturtium Tropaeolum
Red clover Trifolium pratense
Sunflowers Helianthus

This wood-dwelling bee emerges in early spring, at the same time as the early-flowering fruit trees that they pollinate. They forage under overcast skies at temperatures as low as 54°F ( 12°C). They are effective pollinators, visiting up to 2,000 blossoms a day. Effective pollination by mason bees does not require large populations; 50 bees can adequately pollinate a small orchard of a dozen trees.

Bees like to nest in a dry place protected from wind. Somewhere that receives morning sun that warms them up is best, such as under the eave on the southeast side of a house or shed. Orchard mason bees have a limited foraging range of 300 feet (90m) so place bee houses close to the area in need of pollination.

Studies have shown that they pollinate certain crops – apples, cherries, squash, watermelon, blueberries, sunflowers and cranberries – with greater efficiency than honeybees. It was shown that only 250 female orchard mason bees were needed to pollinate an acre of apples, when 15,000 honeybees would be needed to do the same job.

Females are the primary pollinators and the sole nest builders. Males also pollinate, but their foraging is done purely for nourishment. The female lays about 30 eggs in her lifetime, with activity ending in June. Within a week of laying the eggs, the larvae hatch and start feeding on stored nectar and pollen reserves. After two weeks, most of the food has been consumed so the larva spins a cocoon and pupates. Later in the summer, the pupa develops into the adult bee, which remains in the cocoon throughout winter, to emerge again the following spring.

Carolyn’s new book The Zero Mile Diet – A Year-round Guide to Growing Great Organic Food is now available (Harbour Publishing)

Leave a comment