Wonders of Wildlife: Eastern Bumble Bee

Eastern Bumble Bee

Other Common Names: Common Eastern Bumble Bee, Common Bumble Bee

Scientific Name: Bombus impatiens

Found in Alabama: Statewide

Diet: Herbivore (eats plants)

Eastern Bumblee Bee on Flower
Wikimedia – Bob Peterson

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Classification

IDENTIFICATION

Adaptations

Life Cycle

Habitat Needs

Ecological Role

CLASSIFICATION

Scientists use basic traits to
group animals into different taxonomic
classes.

For a taxonomic classification chart comparing key traits of common backyard wildlife,
CLICK HERE!

What type of animal am I?

I am an invertebrate (an animal without a spine or backbone).
I am cold-blooded, so I cannot control my body temperature.
I have a stiff covering on the outside of my body called an exoskeleton.
I breathe through small holes in my abdomen called spiracles.
I have six legs.
I have wings.

The Eastern Bumble Bee is an INSECT!

IDENTIFICATION TIPS

ADULT BEE

Large, furry bodies
Head, abdomen (back section), and legs are black (except for males)
Thorax (middle section) is yellow with a shiny bald spot in the middle
Single band of yellow hairs around waist (on abdomen)

Male (drone) Eastern Bumble Bee
Illustration by Trenton Jung, 2018

QUEEN

Up to 21-23 mm in length
Black with yellow thorax (middle section)

Eastern Bumble Bee Queen
Benjamin Smith

WORKER (FEMALE)

9-14 mm in length
Black with yellow thorax (middle section)

Eastern Bumble Bee Worker (Female)
Photo by Merle Shepard

MALE

12-18 mm in length
Face and head are yellow

Eastern Bumble Bee Male
Bugguide.net – Donna K. Race

Examples of Bumble Bees in Alabama

Eastern Bumble Bee Queen
Benjamin Smith

Large bodied
1-3 stripes of yellow
hair on abdomen
(back section)

Eastern Bumble Bee Worker (Female)
Photo by Merle Shepard

Large bodied
Black head
Yellow hairs on thorax
(middle section)
Band of yellow hair on
abdomen (back section)

Eastern Bumble Bee Male
Bugguide.net – Donna K. Race

Medium sized
Bright metallic green or
blueish head and thorax
(middle section)
Black and yellow striped
abdomen (back section)

PHYSICAL AND BEHAVIORAL ADAPTATIONS

PHYSICAL ADAPTATIONS

Eastern Bumble Bees have pollen pouches:

Eastern bumble bees are, like many bumble bees, important pollinators (animals that move pollen, the powdery yellow substance found in flowers, from one plant to another) for native wildflowers.
As the bees visit each flower, the pollen sticks to their fuzzy bodies.
As they continue to move among the flowers, they transfer pollen from one flower to another.
They also collect and place pollen grains in special pouches, called pollen baskets, that are located on the hind legs.
This pollen is taken back to the hive and used to feed the larvae (baby bumble bees).

BEHAVIORAL ADAPTATIONS

Eastern bumble bees are diurnal:

They are active during the day (diurnal).

Eastern bumble bees are efficient foragers:

Bumble bees have a special way of foraging (searching for food).
The perform a behavior called traplining.
Forager bees (those that go out for pollen and nectar) visit flowers in a repeatable sequence.
This allows bees to know exactly where food sources are, minimizing the time spent searching.
This reduces the distance between food sources, saving time and energy.
They are able to communicate with each other about the direction and distance to a specific food source through movement, often called a “dance”.

Eastern Bumble Bee on Smooth Yellow False Foxglove (Aureolaria flava)
Kristen Irions

Bumble bees can do a special type of pollination:

Some bees, including bumble bees, can do a special type of pollination called buzz pollination.
In buzz pollination, large bees vibrate their wings quickly while visiting a flower.
The vibration causes pollen to release from that flower that would not have released if the flower was not shaken.
Buzz pollination is used to pollinate over 20,000 different species of flowering plants across the world.
Some plants like tomatoes, eggplants, pumpkins, cranberries, and blueberries require this type of pollination.
Honey bees cannot perform buzz pollination.

Eastern bumble bees are able to thermoregulate:

Thermoregulation is the ability of an organism to keep its body temperature within a certin range, regardless of the termperature of the environment around it.
Bees need to be a certain temperature in order to fly, forage (search for food), and incubate their young.
On cooler days, bumble bees will shiver without moving their wings, creating heat in their muscles.
They can do this as a colony or individually.
Although most bees, like most insects, are considered cold-blooded because they cannot generate their own body heat, bumble bees can be considered endothermic (warm-blooded) because of this behavior.

Eastern bumble bees are eusocial:

Eastern bumblebees are considered a eusocial species.
This means they live in colonies and divide responsibilities of foraging (searching for food), defense, and reproductive duties among different castes (groups).
The queen emerges from hibernation (period of inactivity) in the spring and eats nectar to build strength before starting a new colony.
The first to emerge are female workers that forage for food and feed the brood (the young).
Later in the summer, the colony begins producing males and additional queens (which are fed more than the workers).
The queens will eventually leave to start additional colonies the following spring.
In addition to specific tasks for each group, they also distribute themselves in an organized fashion in the nest.
Smaller workers are found near the center and feed the young.
Larger workers are typically found around the edge of the nest and work as foragers (search for food) and guards.

Queen Eastern Bumble Bee with Tongue Extended
Flickr – Sankax

LIFE CYCLE

Life Cycle of the Bumble Bee
GWNews – R. Bishop

Metamorphosis is the process of physical change that some animals go through as they transform from a larvae into an adult.

Four Life Cycle Stages of the Eastern Bumble Bee

Stage 1: Egg

Queens deposit around 2,000 soft-shelled eggs each season, but only half of them will survive to become adults.
Eggs are deposited in paper cups that the queen builds within the underground nest.
The nest is usually built in an old mouse or chipmunk hole.

Stage 2: Larvae

After about 5 days, the soft-bodied larvae will emerge from the eggs.
Males and workers will remain as larvae for 9-10 days, while queens are fed more and will remain in the larval stage for up to 18 days.

Stage 3: Pupa

The inactive pupal stage lasts for about two weeks for queens and around 10-11 days for workers and males.

Stage 4: Adult

As the colony grows, workers (females) are capable of laying eggs.
Unfertilized eggs become males.

Lifespan

Colonies are annual (one generation lasts for one year).
Queens live longer than the males and workers.

HABITAT NEEDS

Natural Habitat Needs	Adults	Young
Food	Adult bees will eat nectar found in flowers as fuel for flight. Most bees in the colony eat honey because it is more nutritional than nectar. Honey is made when bees consume nectar and pollen from plants, then regurgitate (spit up) what they have eaten, mixing them with enzymes in their stomach. Preferred flowers include (but not limited to): Aster, Thistle, Joe-pye Weed, Yellow Jasmine, apple trees, Pickerelweed, Raspberries, Blackberries, Goldenrod, Clover, and Azaleas.	Worker bees are responsible for feedeing the larvae. Raw pollen is typically fed to larvae because it is rich in protein. After metamorphosis (change from larval stage to adult stage), the bees adult bees search for food on their own.
Water	Eastern bumble bees will drink from natural water sources like puddles, ponds, and streams. They prefer “dirty” water that is mineral-rich such as rainwater trapped in a clogged gutter that has grown algae. They may switch their water sources throughout the year based on which nutrients their bodies need most. During much of the year they prefer sodium-rich water, but in the Fall when there is less pollen (powdery yellow substance found in flowers), they switch to water rich in calcium, magnesium, and potassium (all of which are found in pollen).	The food sources (pollen often mixed with saliva or honey) provides enough hydration for the young until the go through metamorphosis (physical change from larva to adult) and can drink on their own as adults.
Shelter	Nests are made underground in old mouse or chipmunk holes 1-3 feet below surface. When away from the nest, they will take shelter under vegetation or flower petals.	Eggs, larvae (the young), and the inactive pupae are all found in paper cells within the underground nest.
Places to Raise Young	Nests are made underground in old mouse or chipmunk holes. Egg clumps are laid all over inside the nest rather than in one particular spot like many other types of bees.

If you want to offer resources in your backyard habitat for this species, consider the suggestions below.

Backyard Habitat Needs	Adults	Young
Food	Plant native plants, including the ones listed above. Do not spray pesticides that might harm insects.	Providing food source for adults will indirectly provide for the young, as the honey fed to the larvae comes from the plants from which adults collect pollen and nectar.
Water	Provide a shallow pond, bird bath, or puddling station. Be sure to include rock for perching, as bees can drown easily.	Providing water source for adults will indirectly provide for the young, as the larvae are cared for by adults.
Shelter	Do not fill in old mouse or chipmunk holes if found. Plant native plants that will offer resting and hiding places.	Proving areas for nesting sites will benefit the young as they are raised within the nest.
Places to Raise Young	Do not fill in old mouse or chipmunk holes if found. You can protect nests from predators by covering it up with a metal grid or something else that bees can still get through but mammals cannot.

ECOLOGICAL ROLE

Bees play an important ecological role in the health of habitats and ecosystems.

Bumble Bees as a Food Source:

Birds, spiders, wasps, and flies will eat individual bumble bees while they are out foraging.
Some mammals will raid and eat the underground nests of bumble bees.

Bumble Bees as a Pollinator

Bumble bees are important pollinators for native wildflowers, fruit trees, and vegetables because of their style of “buzz pollination” that shakes the flower and releases more pollen.
Buzz pollination is used to pollinate over 20,000 different flowering plant species across the world.

There are around 20,000 bee species throughout the world.
Over 4,000 species of bees are native to the United States (U.S.).
Bees pollinate over 130 types of fruits and vegetables.
In Alabama, there are 20 different species of bumble bee!
Eastern bumble bees are not aggressive and will only sting when they feel threatened such as disturbances to their nest or when someone swats at them with their hand.
Unfortunately, many bee species, including bumble bee populations, are declining (becoming smaller in number) in number due to factors like habitat loss, parasites, pesticides and invasive species.
Some of the native bee species found in Alabama include:

American Bumble Bee Cuckoo Bee Eastern Carpenter Bee
Leafcutter Bee Long-horned Bee Mason Bee
Miner Bee Orchard Mason Bee Sweat Bee