Bumblebees are like their honey bee counterparts in their internal anatomy. However, they have noticeable distinctions from each other. Bumblebees are larger, rounder, and bright yellow.
Additionally, each kind of bumblebee – the queen, drone, and worker – is built differently.
How Do You Identify a Bumblebee?
Bumblebees are roughly half an inch to a full inch long. Worker bees are usually half an inch in size, while queens can be as big as an inch. Honey bee workers, in comparison, can be just as long as bumblebee workers. Queen honey bees are not as large as queen bumblebees, however.
Bumblebees are striped and yellow, like their honey bee and carpenter bee cousins. They also look similar to yellow jackets and wasps, which have similar colours.
The bodies of bumblebees are rounder than those of other species of bees and wasps, but carpenter bees are larger.
Bumblebees and carpenter bees are mistaken for each other, but they have one distinctive difference. Bumblebee abdomens are fuzzy, yellow, and hairy, while carpenter bee abdomens are bare, black, and shiny.
What Are the Parts of a Bumblebee?
The bumble bee’s anatomy is separated into three major parts:
- Head: Includes the face and antennae.
- Thorax: The middle of the bee where its wings and legs attach.
- Abdomen: The lower portion that contains the digestive and reproductive organs and stinger.
These sections hold the more distinct parts of bumblebees:
- Eyes: Bumblebees have five eyes – two large compound eyes and three small ocelli.
- Mandibles: These are the jaws of bees. They sit on opposite ends, with one underneath each large eye.
- Tongue: Bumblebee tongues are long and feathery.
- Legs: Bumblebees have six legs with tiny hairs, known as pollen baskets, to transport pollen.
- Wings: Like honey bees, bumblebees have two front wings and two hind wings.
- Pollen Basket: Female bumblebees have two pollen baskets on their hind legs that collect pollen.
- Stinger: Bumblebee stingers are smooth and able to sting multiple times.
Furthermore, male and female bumblebees don’t have the same characteristics.
What Is an Exoskeleton?
An exoskeleton is what protects bumble bees’ bodies. Other creatures with exoskeletons include shellfish and beetles.
“Exo” describes something that is outside. An exoskeleton is a structure that is outside of a body. The opposite would be an endoskeleton, which is what mammals have. Endoskeletons are internal supports, while exoskeletons act like armour.
Exoskeletons are made up of a polymer called chitin, along with proteins, carbohydrates, and lipids. Chitin takes the form of rigid plates with muscles attached to the undersides.
Bumblebees are unable to grow after hatching from their cocoons because of their exoskeletons. Other exoskeleton creatures, such as crabs and spiders, may shed their exoskeleton in order to grow, but bumblebees don’t.
What Can Be Found On The Bumblebee’s Head?
Bumblebees have five eyes, two antennae, and two mandibles on their head.
The bumble bee’s two large compound eyes are visible, but their three ocelli can be hard to spot. Compound eyes are located on the sides of their head, while the ocelli are on the forehead.
Bumblebee antennae are versatile and perform crucial functions. They act as sensors for smells, light, electric fields, and chemicals.
Mandibles are bees’ jaws. They protect the bee’s delicate tongue, which is used to collect nectar.
What Are the Parts of a Bumblebee’s Mouth?
Bumblebee mouths have multiple parts that fold up when the bee isn’t using them. These include:
- Labrum: A front lip that covers the rest of the mouth.
- Mandibles: Jaws that clasp pollen and wax.
- Maxillae: Two long sheaths under mandibles that grasp and shape food.
- Labial palps: Two parts under the maxillae used for their taste sensors.
- Proboscis: A tube protected by the mandible, maxillae, and labial palps. The proboscis collects nectar.
- Glossa: A tongue-like structure that protrudes from the proboscis with a hairy end to collect nectar.
Bumblebee mouths are used for eating, chewing, and creating honey. They are not used for breathing.
What Can Be Found on the Bumblebee’s Thorax?
The thorax is located between the head and abdomen and includes wing muscles, wings, air holes (or spiracles), and legs.
The thorax has two large muscles that control the bee’s wing movement. These muscles are not directly attached to the wings like birds. Instead, the muscles of the thorax cause indirect movement in the wings. A longitudinal muscle pulls from the front to back, while latitudinal muscles squeeze from top to bottom, allowing the wings to move together.
Additionally, bumblebees have three pairs of legs. Their legs are spiked like combs to maximize pollen collection.
Fun Fact:
Instead of noses, bumblebees use antennae for their sense of smell. Antennae have pore plates that connect to sensory cell membranes. These pore plates are used to decipher scent. Along with these olfactory sensors, other hairs and organs on the antennae are used to sense other things like temperature and pheromones.
What Can Be Found on the Bumblebee’s Abdomen?
The bumblebee abdomen holds the majority of a bumblebee’s organs, including the digestive system. The abdomen ends in a stinger, which is located underneath the rectum.
Bumblebee abdomens are characterized by thick hair. This feature keeps them warm and helps in gathering pollen. Seven pairs of air holes line up on their abdomen as well, which are used to pull oxygen into the bee’s body.
How Do Bumblebees Breathe?
Bumblebes’ thoraxes and abdomens have air holes called spiracles. There are 20 individual spiracles on a bumblebee. Each spiracle is attached to a trachea, which moves oxygen through the body.
The trachea brings air to tracheal sacs on the head, thorax, and abdomen. The bumblebee takes in and releases air through abdominal contractions.
How Can You Determine the Gender of a Bumblebee?
The primary contrast between the bumblebee genders is size, except for the queen. Female worker bees are smaller than male drone bees. The queen bees are larger than the male bees.
Female bumblebees are generally rounder and shorter than males. Some additional distinctions include:
- Antennae: Females have short antennae composed of 12 segments, while males have 13 segments.
- Abdomen: Female abdomens are round with six segments. Male abdomens are narrow with seven segments.
- Mandibles: Females have broad mandibles while males have narrow and bearded mandibles.
- Stingers: Only females have stingers.
- Yellow hair: Females have less visible yellow hair.
- Eyes: Some male bumblebees have larger-than-average eyes.
- Pollen baskets: Only females have pollen baskets, which are on the hind legs.
Additionally, male and female bumblebees don’t visit the same types of flowers.
Do Bumblebees Have Pollen Basket?
Bumblebee workers and queens have pollen baskets. Pollen baskets are part of bees’ hind legs and are known as corbicula.
Spiky and comb-like hairs on bees’ hind legs create pollen baskets when the bee pushes pollen and nectar onto them.
Bumblebees are hairier than other nectar-collecting insects. Their entire body collects pollen while they are foraging, which they clean off and transfer to sacs. Often, pollen falls off onto other flowers as they fly through plants.
Bumblebee Body vs. A Honey Bee’s Body
Bumblebees and honey bees are both of the Apidae family, but they have physical distinctions that are easy to recognize.
| Bumblebee | Honeybee | |
|---|---|---|
| Size | 0.6 - 1.06 inches long | 0.5 - 0.8 inches long |
| Shape | Round | Slender |
| Sting | Can sting multiple times | Stings are barbed and can only strike once |
| Wings | Irregularly-shaped marginal cell | Translucent with a smooth marginal cell |
| Temperature | Can withstand colder temperatures due to hairy features | Smaller range of acceptable temperatures |
Both bumblebee and honey bee workers and queens have stingers and venom sacs.
Each Body Part Works in Unison and Individually
The anatomy of a bumblebee is equipped for pollen-collecting, protection, and observing the environment. Each hair and organ has a specific purpose in a bumble bee’s life. Their tell-tale round and hairy characteristics can help you distinguish them from other bee species.
Bumblebees breathe through spiracles, or little holes, on their thoraxes and abdomens. Instead of a nose, they use antennae to detect scents in the air. Bumblebees can grow to about half an inch in length, though some are as long as a full inch.
