While beekeeping generally focuses on honey bees (Apis spp.), some people also keep bumble bees (Bombus spp.). While they don’t produce honey, bumble bees serve a crucial pollination role. The wide variety of bumble bee species (over 250 species worldwide and nearly 50 in the United States alone) pollinate a wide variety of plants. They can even pollinate some flowers that other bees can’t through a process called “buzz pollination”: they grab a flower with their mouths and beat their wings rapidly (over 130 beats per second). The vibration dislodges tightly-held pollen. This makes them critical pollinators for eggplants, tomatoes, peppers, potatoes, blueberries, strawberries, cranberries, and kiwis.
They are also active earlier and later than other bee species. Often the first to emerge in the spring (February) and the last to stop foraging in autumn (November), they pollinate when other bees don’t.
This is also true on any given day. Bumble bees typically begin foraging earlier in the morning and remain out later in the evening than other bees. These characteristics make them important to both agriculture and the environment. They are a desirable bee for professional and amateur beekeepers alike. If you’re considering trying to raise some bumble bees of your own and you’re looking for some tips, you’ve come to the right place.
Bumble bee natural habitat
Where do bumble bees live? Bumble bees nest in cavities, typically underground. They often choose abandoned rodent burrows but also nest in hollow trees, rotten logs, or even drier vents. Their colonies are smaller than those of honey bees, having hundreds of bees to a honey bee hive’s tens of thousands. Most bumble bees die off in the winter, with only a handful of females surviving in hibernation to begin new colonies in the spring. They emerge as the weather warms and seek out a suitable location for a nest. Once a bumble bee queen finds a nest site, she lines it with grass or moss. If she has chosen a rodent burrow, she can skip this step as they are often already lined with fur. Next, she builds wax cells and provisions them with nectar and pollen, lays 5-20 eggs, and incubates them for about a month. The worker bees that emerge from the cells take over the role of foraging. It is during foraging that bumble bees provide their crucial pollination services.
How to make bumble bee nest boxes
You’ll need to make two types of nest boxes: one small (the starter box) and the other large so the colony can grow. Prepare them in winter so they are ready when queens emerge in the spring.
The starter box will be an inverted plastic storage container (4 x 6 x 4 inches). Cut a small square out of the bottom (the top of your nest box) and attach a fine-mesh metal screen that you can lift like a trap door to access the nest. Attach the screen at the back with staples and seal the other sides using putty. Cut a circular hole and attach a medicine dropper as a feeder. On the bottom of the nest box (the top of the container), place another square of the screen with a wax cup and a pea-sized ball of hardened spray foam on it. The wax cup is for syrup and the ball of foam is an egg-laying surface.
Next, make your second – wooden – nest box (6 x 16 x 4 inches). Use ¾-inch plywood and hardware cloth (or something similar) as a liner. Drill ventilation holes and place screen over them. Put screen over the bottom of the box and a plexiglass lid on the top. Instead of drilling a hole for a medicine dropper in the top, drill an angled hole in the side of the box so that a syringe feeder fits snugly.
Set up your boxes in a warm (~78oF), dark area with about 60% humidity. When you need to feed the bees, use a red light so that you can see, but the bees won’t be disturbed. Feed the bees pollen and sugar syrup. The best way to get pollen is from pollen traps set up at beehives. You may be able to purchase pollen from nearby beekeepers. Try to get spring pollen because it is most like the pollen the bees would have collected themselves. Seal the pollen in airtight bags and freeze it. Make sugar syrup in a 1:2 sugar-to-water ratio and refrigerate it.
Populating your nest boxes
You’re finally ready to catch some queens. While you can purchase bumble bees from commercial suppliers, we don’t recommend it. Many natural bee populations are declining, partially due to diseases introduced by non-native commercially-reared bees and competition with cultivated bees for both food and space.
As fertilized female bees emerge in the spring and begin to forage for nectar, trap them with an insect net and place them in a jar. If you see pollen on their legs, don’t trap them. These bees have already started a nest and they won’t start another. Collect a few queens but no more than you have boxes. Put them all into a wooden nest box with a pea-sized ball of pollen and a syringe filled with sugar syrup. To make the pollen ball, mix pollen and a little sugar syrup into a dry dough and roll it into a ball. Leave them overnight before moving them into starter boxes (two queens per box).
Place a pollen ball in each starter box and fill the medicine droppers with 2mL of sugar syrup. Resist the urge to check on your bees for 3 days. This increases the chances of success. After 3 days, refresh both the feeder and the pollen, but give them about ¼ the pollen you supplied originally. Check them every other day after this, feeding small amounts of pollen and maintaining the sugar syrup. Not every starter box will be successful. A good sign is a queen laying on the foam and/or adding wax to the wax cup. She will make little wax cups on top of the foam and lay eggs in them. When the eggs hatch (about 3 days after laying), the queen will need additional pollen to provision the larvae. About a month after laying, the adult workers will leave the cups. If you don’t have eggs after about a month, release the bees.
Once the workers emerge, move your colonies to the larger boxes. Use a red light so you don’t disturb the bees. Place the entire starter box inside the large box and take the top off. Quickly close the lid of the large box. Make sure your syringe is full of syrup. Add syrup every day and pollen every other day. Keep a small surplus of pollen in the box.
When your colony has about 10 workers, move the box outside and open a hole so they can fly out to forage. A flexible rubber pipe or hose will make a good tunnel. Don’t place the box in full sun or it will get too hot. At this stage, you’ll need a wooden lid so the box remains dark. You can leave the plexiglass lid underneath the wooden lid and check in on them from time to time. You no longer need to feed them when they begin foraging for themselves.
Keep in mind!
The colony will last the summer and then die off. If any of your boxes suffered diseases, throw those boxes away. Clean the remaining boxes by soaking them in a 10% bleach solution. Let them dry and store them for new colonies next year.
A simpler nest option
If you don’t want to go through the work of rearing a brood of bumble bees, you can try to encourage a newly emerged queen to nest near your garden by setting up an attractive nesting site. Grab a large flower pot (diameter of over 20cm) and a length of hose or flexible rubber pipe. Dig a shallow hole in the soil and place nesting material (dry grass, moss, or rodent bedding from a pet store) in it. Poke drainage holes in the hose or pipe and bury it in the ground so that one end emerges in the hole and the other emerges outside the hole. This will be the bees’ tunnel in and out. Flip the flower pot upside down in the hole and partially bury it to make a bumble bee nest in the ground. Place a piece of slate or tile over the pot’s drain hole so rain doesn’t get in. There is no guarantee that a queen bumble bee will choose your nest site, but she might.
Bumble bees are crucial pollinators for natural habitats and gardens, pollinating a wide variety of flowers. They are unique in their ability to buzz pollinate, which allows them to pollinate species that other bees can’t. This makes them great to have around. Here, we’ve outlined the difference between bumblebee vs honeybee keeping, reviewed their natural habitat and life cycle as well as two different ways to make bumble bee nests, one more involved than the other. We hope this provides you with enough information to get your bumble bee colony started. Good luck!