Bumble Bees

• Bumble bees are social insects that live in colonies with other bees. Seeing multiple bumble bees is a good indication there is a bumble bee nest nearby.
• Bumble bees typically nest in dry, protected, pre-existing cavities. They can be below ground, such as an empty rodent burrow or a void in or under a structure; or on or near ground level in rock piles, under piles of wood on the ground, or under piles of dead leaves and compost piles. The queen constructs the nest using dry grass and other plant material to form an insulation layer. She then constructs a wax cell for her eggs.
• Bumble bee nests are used only once and then abandoned.

• Like other insects, A bumble bee’s body has three sections; the head, thorax, and abdomen.
• There are 6 legs and 2 sets of wings attached to the thorax.

Workers:

• The thorax is densely covered with short hairs.
• Depending on the species, the face is black, the first segment of the thorax is yellow, the second is black, and third is black with a very narrow yellow band at the rear.
• The wings are dark-colored.
• Bumble bee workers are 11/16” – ¾” in length.

Queens:

• Similar to workers, but are larger (3/4” – 1” in length) and appear earlier in the season.

Rusty-patched bumble bee

• The hairs on the 1st segment of the abdomen are yellow.
• The 2nd segment is mostly yellow, but with a central patch of rusty-brown-orange hair at the front edge of the segment, going about half way back. This rusty-patch (for which the bumble bee is named) can be subtle and varies in color from brown to orange.
• The remaining segments of the abdomen are covered with black hair.
• The hairs on the thorax are yellow except for a T-shaped area of black hairs between the wings with a thin line extending down the middle towards the back of the thorax.
• The rusty-patched bumble bee is not the only species of bumble bee with “thumb-tack” coloring on the thorax, so look for both the “thumb-tack” and the “rusty-patch” on a bee to be sure.

The University of Minnesota Extension offers a downloadable Bumble Bee Identification resource. Click to view.

• Bumble bees are not as aggressive as hornets and yellow jackets.
• Males cannot sting, and females only do so when they feel threatened or when their nest is disturbed.
• Bumble bees can sting repeatedly and will not die afterwards, since their stingers are not barbed and won’t dislodge from their body.
• Bumble bee stings are painful and can be a health threat to people with allergies.

• Bumble bees collect nectar (carbohydrates) and pollen (protein) from flowering plants.

Bumble bees collect nectar, store nectar, and do make small amounts of honey. However, bumble bees do not store large quantities of honey like honeybees.

• Bumble bees are excellent pollinators for several reasons.
• Their relatively large, fuzzy bodies are great for collecting pollen from the plant.
• Bumble bees then brush the pollen onto their hind legs, where special hairs help hold it in place as they fly around. You may see these large yellow or orange “balls of pollen” on the bumble bee’s legs.
• Most bumble bees visit a wide variety of flowers. Some plants, like tomato plants, need the vibrating of the bees’ wings to shake the pollen grains out of the plants’ anthers.

• Worker bees and males who have left the nest may be found sleeping in flowers. Bumble bees prefer it hot -- 80-90 degrees -- in order to fly easily without using up all of their nectar stores.
• A bumble bee that is outside the nest when the temperature drops may spend the night in a flower.
• Also, recent research from Queen Mary University of London indicates bumblebee queens rest for an average of about 30 minutes and sometimes up to almost 45 minutes between very short dispersal flights.

• Bumble bees live in colonies composed of a single queen and female workers.
• Bumble bees go through 4 stages: egg, larva, pupa, and adult.
• In spring, the new queen emerges from underground where she spent the winter, and looks for a new nest site.
• The new queen lays eggs and cares for the colony until the first workers emerge. Once the first workers emerge, the queen stays in the colony laying eggs.
• Bumble bee workers collect nectar and pollen from flowers which they feed to larval worker bees. However, bumble bees do not make and store large quantities of honey like honey bees.
• New queens and males are produced in mid- to late summer.
• By late fall, the colony has died out except for a few final workers and males. The new queen burrows into the ground and enters diapause (a suspended activity stage) to survive the winter. Diapause is similar to hibernation in that the queens are dormant and no longer forage, feed, or reproduce.
• Bumble bee colonies are annual.