Our Most Important Pollinators

Hariette Henry – Halton Master Gardener

Bees are the most economically important group of insects in our landscape due to their pollination of agricultural crops . Though these benefits are often attributed solely to European honey bees (Apis mellifera), native wild bees are responsible for a large proportion of the economic benefits as well. Wild bees are also crucial for the pollination of most non-crop flowering plants, and thus play a very significant role in terrestrial ecosystems. There are approximately 800 species of bees in Canada and roughly 400 in Ontario.

Where do bees fit in to the history of life on earth?

They arose 144 million years ago at the beginning of the Cretaceous period when they diverged from their Apoidea wasp relatives. That was also the period when flowering plants first appeared. Predacious beneficial insects use nectars as sources of energy to fuel flight. Bees not only use nectar for energy, but they use it as an ingredient in the food they collect for their offspring (along with pollen). So it could be said, that it was at this time that bees became vegetarian. They evolved particularly efficient nectar sucking equipment and their mouthpart structure diverged rapidly. Characteristics associated with different mouthparts (also called tongues) are often used by melittologists (an entomologist specializing in the study of bees) in attempting to classify bees into major evolutionary lineages. There is a tremendous diversity in appearance, nesting behaviour and feeding habits of native bees. Some collect pollen from a wide variety of flowers. Others are more restricted in their dietary breath. They range in size from 2mm to 39mm and many are extremely hairy while some are quite bald. They come in a variety of colours, even green. Most are solitary (about 90%), however sixteen species of bumble bees in Ontario live together in hives. Some live in abandoned burrows, others in pithy stems and others in wooden snags. As insects, bees have an external skeleton. They have three pairs of legs, and a body in three parts: the head, the thorax and the abdomen. Bees are under threat from all sides; they have natural enemies such as parasitoids, food thieves and other bees. They are at risk from environmental factors such as weather and climate change. They must contend with disease and introduced species. Those who live in the ground are at risk of drowning. They risk losing feeding, nesting and overwintering habitat and they are at risk from chemical pesticides.

What can gardeners can do to help?

Plant a pollinator garden, become familiar with and learn to identify the native bees in our area and report sightings of species at risk to organizations such as “Friends of the Earth”, The Ministry of Natural Resources and Forestry and iNaturalist.

The poster at right reflects the 16 species of bumble bees that currently reside in Southern Ontario. They are generalist foragers and as such do not depend on any one type of flower. They are often the first bees active in late winter and the last in fall. Since they are active for so many months, they must be able to forage on a wide variety of plant species in a wide range of weather conditions to support a colony. Early and late season food resources (blooming flowers) are critical at these times for the successful establishment and reproduction of the colony.

To Download this lovely poster, go to:

More Information on Bumblebees


Bumble bees are quite large (13-25 mm in length) and are covered in hairs. This and their wide bodies are their most recognizable features. They are typically black and yellow with clear wings however there are variations.


A bumble bee returns to its nest in an abandoned rodent burrow. Image:

Most bumble bee species are social bees and live in colonies with different divisions of labour or castes. They occupy small hives of about 150-200 bees. Their hives are usually found underground in abandoned rodent burrows, although they can also exist in hollow trees, abandoned bird nests, rock walls or under a tussock of grass.

Foraging/Buzz Pollination

Yellow-Banded Bumble Bee (Bombus terricola), one of three at risk bumble bees in Southern Ontario.
The other two are Gypsy Cuckoo Bumble Bee (Bombus bohemicus) and Rusty-Patched Bumble Bee (Bombus afinis). Image:

Bumble bees are able to fly in cooler temperatures and lower light than other bees and they perform a behaviour called “buzz pollination”, in which the bee grabs the pollen producing structure in her jaws and vibrates her wing musculature. This causes the flower to release more pollen than it would otherwise. Some plants including tomatoes and peppers benefit form this “buzz pollination”.

If you would like to do more and learn more about the Rusty-Patched Bumble Bee and Ontario’s native bees in general, the above booklet, published by Friends of the Earth Canada in support of Toronto’s Pollinator Protection Strategy is free to download here.

To Learn More About Bumblebees, Watch:

Cover Image: A Rusty Patched Bumblebee

search previous next tag category expand menu location phone mail time cart zoom edit close