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Cooperative Extension Service |
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Agricultural
Experiment Station |
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Aquaculture
Dale Bumpers College
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Beekeeping - Apiculture in Arkansas
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| Wings Compound eyes Antennae Branched setae Legs Pollen basket Proboscis Wax glands Mandibles Warning colors Stinger |
![]() Photo by David Cappaert, bugwood.org |
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Wings The ability to fly far and fast has greatly contributed to the success of bees. They can forage up to three miles from their hives, and reach speeds of 15 miles per hour. Bees have four wings, but a row of small hooks, called hamuli, on the leading edge of the hindwing fits securely into a groove on the trailing edge of the forewing, allowing the bee to couple the wings together into a single flight surface. When at rest, the bee can unhook its wings and fold them back. (Photo by Jon Sullivan,
pdphoto.org). |
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Compound eyes Each of a honey bee's compound eyes contain over 6500 separate facets, allowing it to see in front, to the side, above and below itself. In addition, bees can perceive all the colors visible to humans except for red, which appears black to them. Honey bees, like many other insects, can see UV light as a separate color, which we cannot. Bees can also detect the polarization of UV light, which aids their navigation on cloudy days, when the sun is not visible in the sky. Bees also have three simple eyes, called ocelli, that are grouped together near the top of the head. These are sensitive to light, but cannot focus an image, and are likely used to orient to light. (Photo by Scott Bauer,
USDA). |
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Antennae A bee's
antennae are covered with thousands of sensory cells for touch and
smell. A bee's sense of smell is much more acute than any mammal's and
is very important locating food and in communication between hive
members. These sensitive organs also relay information about air speed
and orientation during flight. |
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Branched setae The bee's body is covered with branched setae, or feathery hairs. Pollen grains stick to these hairs as the bees forage on flowers. Some of the pollen is transferred to new plants, resulting in fertilization of the flowers. The rest is later combed into the pollen basket, and carried back to the hive. Most insects have some setae on their bodies, which aid in their sense of touch, but these finely branched hairs are unique to the bees. (Photo by Petr Kratochvil,
www.publicdomainpictures.net). |
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Legs The bee's six strong legs provide a very stable base for walking or standing, ensuring that at least three feet can contact the surface at all times when moving. Each foot is equipped with claws for grabbing uneven surfaces, as well as a sticky pad for gripping smooth surfaces. Each pair of legs is also equipped with special structures and arrangements of setae for grooming the body or pollen and debris. (Photo by Scott Bauer,
USDA). |
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Pollen basket The pollen basket, or corbicula, is made of long stiff hairs that curve around a wide flattened section of the honey bee's back leg. Stiff hairs on the other legs are used to comb pollen grains from the bee's body, which is compacted and stored in the pollen basket for transport back to the hive. (Photo by Scott Bauer,
bugwood.org). |
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Proboscis The honey bee has a long tongue, or proboscis, which it uses to lap up nectar from deep inside of flowers.
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Wax glands Wax glands on the underside of the bee's abdomen secrete flakes of beeswax, which is used to build the honeycombs. Many bees work together to produce and form the wax that becomes their home. Bees must consume at least eight pounds of honey in order to metabolize one pound of wax. (Photo by Zack Huang,
cyberbees.net). |
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Mandibles These
mouthparts, or mandibles, are strong and very useful. The jaws
are attached to powerful muscles, and can be used to pick up and
remove debris from the hive, to attack intruders, and to delicately
manipulate the wax into perfectly formed honeycombs. |
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Warning colors Yellow and black stripes are nature's warning colors. Like many wasps and bees, these highly visible markings warn other animals that the insect can be dangerous. Many harmless flies have adopted these colors as well, to fool predators into thinking they may be able to sting. (Photo by Jon Sullivan,
pdphoto.org). |
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Stinger The stinger is used by the bee only for defense. The end is barbed, like a fish hook, so it can penetrate skin, but not easily come out. When a bee stings, its stinger and attached venom sac is torn from her abdomen, and she will die shortly afterward. Honey bees are not naturally aggressive, and are reluctant to sting unless they feel that they, or their nest, are threatened. The shaft of the stinger is a modified ovipositor (egg-laying structure), and is therefore only found in worker bees. The queen bee's ovipositor is not barbed, and is used for egg-laying, but she can sting rival queens and occasionally will sting a careless beekeeper if she is mishandled. (Photo by Scott Bauer, USDA). |
Like all insects, a honey bee's body is divided into 3 segments: the head, thorax, and abdomen.
See below to explore the inside of the bee in detail.
| Head Thorax Abdomen Brain Ventral Nerve Cord Hypopharyngeal gland Pharynx Esophagus Honey crop Stomach Hind gut Malpighian tubules Salivary glands Heart Venom sac Antenna cleaner Mid tibial spur Pollen press |
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Head The head is dominated by large compound eyes, sensitive antennae and a complex arrangement of mouthparts. The bee's head also houses the brain and contains several important glands. |
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Thorax The thorax
is primarily used in locomotion, as the attachment site for six legs and
four wings. The ventral nerve cord, heart and esophagus pass through,
but most of the space inside the thorax is taken up by sets of powerful
flight muscles. Salivary glands are located ventrally, near the front of
the thorax, connecting by a duct to the oral cavity in the head. |
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Abdomen The abdomen
protects the organs for the digestive system. Also present are the
heart, venom sac, and several glands. The reproductive organs are
also located in the abdomen. In a laying queen bee, the ovaries take up
much of the space here, and account for the larger size of the abdomen.
Among the sterile worker caste, however, these remain undeveloped. |
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Brain The brain
appears dominated by the optic lobes, which process the visual input
from the large compound eyes. Honey bees also have excellent memory
processing and learning abilities, necessary for long foraging flights
away from their hives. The brain coordinates and regulates the functions
of all the bodily systems. While only about 1 cubic millimeter in size,
the honey bee's brain contains some of the most densely-packed
neuropil tissue known in any animal brain. |
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Ventral nerve cord The
ventral nerve cord runs the length of the bee's body, connecting
the brain with all the other organs and systems. Numerous ganglia along
the way assist in coordinating local neural processing. |
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Hypopharyngeal gland
Worker bees possess a hypopharyngeal gland that produces royal
jelly, or bee milk. This rich blend of proteins and vitamins is fed to
all bee larvae for the first three days of their lives, after which
workers and drones are fed a mixture of pollen and honey. When a female
larva is fed continuously on royal jelly, she will rapidly develop into
a queen bee. This nutritious diet will remain the only food that a queen
will ever consume, allowing her to maintain a high level of continuous
egg production. |
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Pharynx The pharynx is the first section of the alimentary canal. Strong muscles here provide suction to draw in nectar from flowers. This is also the site for taste reception in insects.
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Esophagus The bee's
esophagus is little more than a thin tube connecting the pharynx and
crop. Their diet of honey and pollen does not require a powerfully
musculated esophagus as in vertebrates. |
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Honey crop The honey
crop (also called the honey stomach) is where the worker bee stores
collected nectar for the trip back to the hive without digesting it. A
muscular valve called the proventriculus can be closed, keeping the
nectar from passing into the stomach. The crop is expandable, allowing
the bee to carry a larger load. Back in the hive, the contents of the
crop can be ejected back through the mouth for storage in a honey cell
or to feed other bees by trophallaxis. |
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Stomach The true stomach (or ventriculus) is the site of primary digestion for pollen and nectar. Coiled around in the abdomen, it is actually about twice the length of the bee's body. The epithelial cells that line the stomach wall are the site of attack by the microsporidia Nosema.
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Hind gut The hind gut
is composed of the intestine and rectum, where reusable metabolic
products are reclaimed and excess water is reabsorbed into the body. The
rectum is also distensible, and can hold a large volume of waste matter.
Bees keep meticulously clean nests, and will hold their wastes until
they can make a "cleansing flight" outside of the hive. In climates with
long, cold winters, bees can actually wait for weeks or months to
perform this task. |
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Malpighian tubules
Numerous Mapphigian tubules connect to the basal end of the hid
gut and float freely in the abdominal cavity. They function much like
the kidneys of vertebrates, removing excess salts and metabolic wastes
from the blood and concentrating it into the intestine, where it can be
removed. |
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Salivary glands
Salivary glands are located in the front of the thorax, and
connected to the mouth by a duct. This gland produces enzymes which aid
in the breakdown of food. In particular, an enzyme called invertase is
released, which functions to break down the sugars in nectar, and is
essential to the process of converting it into honey. |
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Heart An insect's heart
is simply a series of musculated chambers connected the aorta, a tube
that runs forward to the head. When relaxed, blood from the
abdominal cavity enters the heart chambers through openings called ostioles. When it contracts, the ostioles close, and blood is forced
forward through the aorta to the brain, and then circulates back through
the thorax, bathing all the organs and muscle tissues along the way.
This type of open circulatory system is well well-suited for a small insect.
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Venom sac Connected to the
stinger is a venom sac, which holds a mixture of protein
chemicals (the venom) and alarm chemicals. These proteins can quickly
cause a painful localized reaction in vertebrates, which can be severe
to life-threatening in highly sensitive individuals. When a bee stings,
the barbed shaft of the stinger is left behind, along with the venom sac.
An attached muscle continues to pump venom through the stinger, even
after it has been disconnected from the bee. For this reason, a bee
stinger should be removed immediately by scraping it with a credit card
or pocket knife blade, and not by pinching it, which can forcibly inject
the venom into the skin. |
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Antenna cleaner The
antennae are important sensory organs for the bee, which must remain
clean in order to function effectively. Each of bee's front legs is
equipped with an antenna cleaner. This specialized notch is lined
with numerous fine, stiff setae. As the shaft of the antenna is drawn
through, debris is removed. The tibial spur on the front legs helps to
hold the antenna against the notch. |
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Mid tibial spur The tibial spur of the middle legs can be used to stab the fresh wax flakes secreted by glands on the lower abdomen. The wax can then be transferred to the mandibles where it is be shaped and positioned on the comb.
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Pollen press The pollen press is located just below the pollen basket on the hind legs. As pollen is combed from the rest of its body, the bee uses this leg joint to compress the grains into a dense mass, which can be more efficiently stored in the corbicula.
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For further reading, The Anatomy Of The Honey Bee by R.E. Snodgrass is now available online through the Google Book archive.
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© 2006 |
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University of Arkansas • Division of Agriculture |
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