The Busy Bumble Bee

—Henry Myers, Environmental Education

Bombus impatiens worker foraging on cultivated sunflower. Photo: Leif Richardson.

Finally spring has arrived!  For someone interested in bees, like me, this is the start of a very exciting season.  The honey bees that have been huddled together all winter keeping warm are getting back to business, collecting nectar and pollen; some of the sweat bees and mason bees that spent the winter as larva or pupa, are continuing their metamorphosis; and, bumble bee queens are waking up after a winter of torpor.

The queen bumble bee's life starts in July.  Up until this point, her mother has been emitting a pheromone that controls her daughters, making them worker bees.  In July, she stops producing this pheromone and the new female bees are able to develop into new queens.  These new queens will spend up to a few weeks in the nest feeding on honey and pollen.  

Once the new queens have built up their fat reserves, they will head out of the nest to mate.  In many cases a new queen will mate with just one male.  After mating she will look for a place to hibernate, usually underground.  Hibernation lasts from late July/August until the first warm days of spring so, the bumble bees we're seeing now are queens!

This is a very busy time of year for the new queens.  They need to build back their fat reserves and search for a nest site. These nest sites are usually underground.  Once they have found a nest site, they will build a loose ball out of insulating material and make a honeypot (a wax bowl that they fill with honey) inside of it.

Next, she will forage for nectar and pollen.  Once she has collected enough pollen, she will form it into a ball and make a groove down the middle of it.  She will lay 8 to 16 eggs in this groove. Then she will lay on top of the eggs and vibrate to keep them at 86 degrees Fahrenheit.  She will keep the eggs at this temperature even if the outside temperature drops below freezing.  All of this vibrating requires a lot of energy--to fuel this the queen needs to visit around 6,000 flowers a day! 

All of this hard work is rewarded when the first brood reaches adulthood and the queen no longer has to forage.  Her daughters feed her and help her take care of the new batch of brood.

So this spring while you're out in the garden or taking a hike, look for these amazing insects!

Check out this cool video of a queen bumble bee beating the cold.

For more pollinator information check out the Xerces Society!