Saving our native Humble Bumble Bee

What’s the big buzz about Bumble bees?

Could there be a better bee than our humble Bumble?

A tireless worker that really does not get the credit it deserves. While the non-native honey bee gets the spotlight in the media and just about anywhere climate change comes up, our native Bumble Bee just keeps going about its business and getting the job done.

And quite the job it does.

The Humble Bumble Bee deserves a lot more credit for the work it does in our gardens and agricultural fields.

In case you are not aware, the Bumble bee is the one that brings those juicy tomatoes to your table. In fact, without them, there’s a good chance you wouldn’t be chowing down on that spaghetti or toasted tomato sandwich.

It’s the Bumble bee that is the primary pollinator of tomatoes, not the honey bee.

Why? you may ask.

Bumble bees, unlike honey bees, are capable of buzz pollination. The problem with pollinating tomatoes is the fact that on most flowers the pollen is located out on the end of a stalk on the anthers and easily accessed by most pollinators.

However, explains Paige Embry in her informative book Our Native Bees, “some flowers, including those of tomatoes, hide their pollen inside the anthers so it has to be shaken out. A Bumble bee does this by grabbing the flower in its mouth, curling its body around the anthers and rapidly contracting muscles in its throax, causing vibrations that shake the pollen right out of the tiny holes in the anthers, like shaking salt from a shaker. This activity makes a buzzing noise, and so, buzz pollination.”

So the next time you pick a tomato from your garden, you can thank our humble Bumble Bee.

For more on how we can help save our native bees, check out my story on making a lawn for native bees.

But most tomatoes these days are grown in greenhouses throughout the year. The challenge that faced commercial growers was how to pollinate these tomato plants in a greenhouse, in the winter when there are no Bumble bees around to get the job done.

Going back to 1891, scientists tried to unlock the secret to pollinating tomato plants without the Bumble bee, to very limited success.

Then, according to Embry: “in 1985, Roland de Jonghe a Belgian vet and bee enthusiast put all the bee rearing information together with the fact that a colony of Bumble bees could pollinate a greenhouse full of tomatoes way better than a bunch of people with vibrators or blowers. Since Bumble bee nests only last a few months, people would need new nests every year, and de Jonghe saw the business potential of those Bumble bees. In 1987, he started the first business rearing Bumble bees for commercial use. … By 2004 close to a million colonies of Bumble bees pollinated nearly 100,000 acres of greenhouse tomatoes worldwide, with an estimated value so large that I thought it was a typo accept it was written the same way twice. 12,000 million Euros (about $14 billion) per year.”

Okay, so we now we know the value of our native Bumble bees.

Let’s now take a closer look at these interesting, almost cuddly little creatures with the furry backs.

Do Bumble bees live in hives?

Bumblebees, of the genus Bombus, are common native bees and are important pollinators for many of our woodland wildflowers. Like honeybees, they are social and live in a hive, but one that is the fraction of the size of a honey bee colony – think hundreds rather than thousands.

How many different types of Bumble bees exist?

In the United States alone there are 49 species of these native bees, separated into three different classes depending on the length of their proboscis, or tongue – short, medium, and long. The length of their proboscis will help dictate which species pollinates the various flowers, although some short-tongued Bumble bees have come up with an ingenious way to feed on Long-tube flowers by biting holes in the flowers near the nectar source and feeding through the hole.

Are Bumble bees threatened?

According to the United States Forest Service, Bumblebees have become a conservation issue, resulting from habitat fragmentation caused primarily by human activities, the use of pesticides, as well as disease transmission and the loss of native floral resources.

In the U.S., just in the past few years, two species of Bumblebees have likely gone extinct: Franklin’s bumblebee (Bombus franklini) originally found in a restricted geographic range from southwest Oregon to northwest California; and another species from the eastern United States, which was once found from Canada to North Carolina.

In Ontario alone, there are three at-risk bumble bee species: Rusty-patched (Bombus afinis), Gypsy Cuckoo (Bombus bohemicus) and Yellow-banded (Bombus terricola).

Where do Bumble bees live?

Bumble bees, like most native bees, are primarily ground nesting bees. In spring, the queens begin to emerge from underground where they have spent the winter, and begin to look for a nest site, which can include an already existing but abandoned mouse or rodent burrow.

Bumblebees visit flowers where they feed on the the nectar and pollen. Once their eggs have hatched, they use the plant resources to feed larval worker bees. Unlike honey bees that store large quantities of honey in order to survive winter, Bumble bees may use empty cocoons for short-term storage of nectar.

In a single summer, the Bumble bee queen produces a few generations of workers, which then take over the task of collecting nectar and pollen and help rear the final generation of the colony, which includes queens for the next summer, and males to mate with them.

The colony has all but died out by late fall. All that remains is a few workers and males, as well as the the new queens. These bees burrow into the ground to wait out the cold winter to, once again, begin the process the following spring.

How can we help Bumble bees?

There are reasons you often see native gardeners promoting the practise of leaving your leaves where they fall to help insects and other fauna survive winter.

Well the Bumble bee is a good case in point. Queen Bumble bees overwinter in our gardens in underground burrows and the leaf cover provides protection and helps hold in heat that is vital to their survival.

Check out my earlier post on Why We Need to Leave Our Leaves.

So, in addition to leaving your leaves on the ground in the fall and over the winter, it is also important to provide the native bees with plenty of fall flowers, especially native plants like asters and goldenrods. These late blooming plants are an important food source to enable next year’s queen bees to build up stores of food to last them through the winter in their dormant state.

In addition, refrain from digging up your gardens in early spring to allow the queen bumble bees to leave their underground burrows and begin their new hives.