External Anatomy of the Adult Honey Bee -...

External Anatomy of the Adult Honey Bee

a lesson plan by Louise I. Lynch, Bees Louise!

and Dr. Marion Ellis, University of Nebraska-Lincoln

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L. I. Lynch

External Anatomy of the Adult Honey BeeSee www.beeslouise.org for more bee lessons!

Target AudienceGrades 8th through 12th

Number of Class Periods to Complete Lesson1-2 class periods (60-120 minutes) to introduce topic and complete dissection.Additional activities are provided and may require additional time.

OverviewHoney bees are humankind’s most significant agricultural pollinators, responsible for one third of the food we eat in the United States. Honey bees are highly social insects with colonies of thousands of bees, each individual with it’s own tasks to perform. These pollinators have a mutualistic relationship with angiosperms, or flowering plants, Earth’s most successful plant life form. The study of this insect’s external anatomy provides insight into a significant coevolutionary relationship and the physical adaptations that make the honey bee such a valuable component to our food supply.

This 1-2 period lesson will discuss the unique anatomy of adult bees, their life cycle, physical appearance and biology and the adaptations of bees as pollinators. Students will be guided through the study of a honey bee’s external anatomy and will learn the name and function of structures on the head, thorax and abdomen.

Learning ObjectivesEach student will construct a bee costume and learn the name and function of each structure. As a result of carrying out this activity, students will develop:

• An understanding of honey bee classification and life cycle• An understanding of the structures and functions of an adult honey bee’s anatomy• An understanding of pollination• An understanding of the anatomical adaptations of honey bees as pollinators• Knowledge, skills and abilities required to work with a group

National Science Education Standards from www.nap.eduUnifying Concepts and Processes Standards

• Evolution and equilibrium• Form and function

Life Science Standards• Structure and function in living systems (Levels 5-8)• Diversity and adaptations of organisms (Levels 5-8)• Regulations and behavior (Levels 5-8)• Biological evolution (Levels 9-12)• Interdependence of organisms (Levels 9-12)

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http://www.beeslouise.org

http://www.beeslouise.org

http://www.nap.edu

http://www.nap.edu

Materials Needed1 Lab report per student (from beeslouise.org)1 Dissecting or compound microscope per student pair1 Ruler per student pair2 Forceps per student pair1 Female worker bee per student pair (obtain from local beekeeper)1 Microscope slide per student pair3 Cover slips per student pair

Background Information on the BeeClassification. Bees belong to phylum Arthropoda because they are invertebrates (backbone absent) with an exoskeleton, jointed legs and a segmented body. Bees belong to class Insecta because they have 6 jointed legs, a 3-segmented body (head, thorax and abdomen), 2 compound eyes and 2 antennae. Bees belong to the same order as wasps and ants, order Hymenoptera. ! ! ! Kingdom! Animalia! ! ! Phylum! Arthropoda! ! ! Class! ! Insecta! ! ! Order! ! Hymenoptera (Bees, wasps, and ants)! ! ! Family!! Apidae (Carpenter bees, bumblebees, sweat bees, etc.)! ! ! Genus!! Apis (Honey bees, 7 recognized species)! ! ! Species! mellifera (“honey-bearing”)

Bee life cycle. Bees exhibit complete metamorphosis. They begin their life cycle as a tiny white egg. This hatches into a white, worm-like larva. After feeding on pollen and nectar for several days, the larva develops into a pupa within a cocoon. Finally, a winged adult emerges. In a honey bee hive, only the Queen lays eggs. The rest of the females are workers, carrying out the many tasks of an active hive.

Bee Body Segmentation. The bee has three body regions, as do all insects.1. The head: this segment aids in sensing the environment and feeding. It has two large

compound eyes, three small simple eyes called ocelli, two segmented antennae and a mouth with several appendages such as mandibles and a glossa (tongue).

2. The thorax: this middle segment of the body aids in locomotion. It has six legs, four wings and it contains the muscles required for flight and leg movements.

3. The abdomen: this posterior segment of the body aids in reproduction and defense. It contains the reproductive organs and, in female bees only, a stinger at the very tip.

Bee Anatomy. Bees have many unique body parts each with a specific function.• Compound eyes. Bees have two large compound eyes located on the front of the head. Each eye

is made up of thousands of small eye facets called ommatidia (ommatidium, singular). The brain of the bee interprets the images captured by each ommatidium. Bees cannot see the color red but see all the other colors of the visible light spectrum in addition to ultraviolet (UV) rays. Vision is important for locating flowers, the nest, other hive mates, predators, etc. Many flowers have UV patterns on them that bees can see but we cannot! These patterns help guide the bees to nectar in the flower.

• Ocelli. Bees have three simple eyes, called ocelli (ocellus, singular), located on top of the head in a triangular configuration between the compound eyes. These simple eyes do not form images,

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rather they sense light and dark. The ocelli may be used to sense when the sun is going down providing the bee with a sense of time.

• Antennae. Bees have two segmented antennae (antenna, singular) attached to their head. The antennae are covered with sense hairs, primarily associated with the sense of smell. Important odors include pheromones, flowers, predators, smoke, etc. The antennae are believed to also provide information about temperature, humidity, carbon dioxide levels and taste. Since the antennae are paired, the direction of an odor can be determined (much like we can determine the direction of a sound with two ears). The forelegs have a notched brush used to clean the antennae. Each antenna has a Johnston organ, located in the small, second segment, that provides information about flight speed.

• Mandibles. The bee’s mouth is made up of several appendages. The tooth-like mandibles are the most visible and are used to chew pollen, gather resins, mold wax into cells, etc.

• Glossa. A bee’s tongue is called a glossa and it is located in the mouth. It may be visible sticking out below the mandibles. The glossa works much like a straw and is used to siphon liquids such as water, nectar and honey.

• Legs. Bees have 3 pairs of segmented legs attached to their thorax: the forelegs, middle legs and hind legs. Beginning at the thorax, the leg are: coxa (short, attached to thorax), trochanter (short), femur (long), tibia (long), tarsus (long, divided into a long basitarsus and several small segments called tarsomeres), and finally the pretarsus (foot). All of the legs are involved in locomotion (movement).

a. The pretarsus (foot) has claws that allow the bee to hold onto rough surfaces. The feet also contain small sensory organs allowing bees to taste. They taste with their feet!

b. The forelegs contain an antenna cleaner at the top of the tarsus. The bee can wrap this notched groove around the antenna, and remove any dust or particles by pulling the antenna through.

c. The middle legs have no special features, however they help collect pollen off the body and direct it towards the pollen baskets on the hind legs.

d. The hind legs contain the famous pollen baskets, or the corbiculae (corbicula, singular). Each broad basitarsus has a pollen brush used to brush and collect pollen scattered over the body. The pollen is passed to a pollen press, a toothed area between the tibia and basitarsus of the hind leg. Here, the pollen is pressed into a more solid mass. These little pellets are collected on the corbicula, an area on the outer surface of the hind leg’s tibia, containing long, curved, stiff hairs.

• Wings. Bees have four wings, two forewings and two smaller hind wings, attached to the thorax. Wings are thin outgrowths of the exoskeleton. The arrangement of veins on an insect’s wing is an important characteristic used for species identification. Further, these veins strengthen the wings and feed nerves, blood and air throughout the wings. Flight is controlled by two sets of flight muscles in the thorax. Flight is powered by sugar acquired from nectar and honey. The wings on each side of the body are held tightly together by hamuli, small hooks, on the hind wing that fit into a deep fold on the forewing. This allows synchronized movement. Flight affords bees the ability to travel, forage, carry pollen back to the hive ,cool the hive, escape predators, etc. A flying bee’s wings can complete 200 to 250 cycles per second and they can reach flight speeds up to 15 miles per hour.

• Abdomen. There are 6 visible segments on a bee’s abdomen. The abdomen contains the digestive and reproductive organs. Along both sides of the abdomen, bees have small, circular openings in their exoskeleton called spiracles. These are the openings to a network of air-filled

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breathing tubes that allow bees to take in oxygen and release carbon dioxide. They will most likely not be visible under the microscope. Young bees have active wax glands on the ventral surface of their abdomen. The glands produce liquid wax which is released into small depressions where it dries and hardens. These small, white wax scales are collected and used to build the hive’s comb. Only female bees have stingers, located on the tip of their abdomen. Bees sting defensively. They willingly sting only if provoked or harmed. Their stingers are barbed thus it gets pulled out after stinging, causing death. The stinger in class specimens may be retracted and thus not visible under the microscope.

Pollination Adaptations. Bees are well adapted for their role in pollination. Pollination is the transfer of pollen from the male parts of a flower to the female parts. Pollination is how most of Earth’s plants reproduce and make seeds. The hairs covering a honey bee’s body (and even eyes!) have an electrostatic charge that attracts pollen and lets it stick to the body. Honey bees tend to visit the same plant species, ensuring pollen is passed between the right flowers and permitting fertilization and seed production. A honey bee can visit up to 3,000 flowers in a day! Pollen is the protein-rich food source used to feed the hive’s brood. Bees also sip nectar, a sugary liquid produced by flowers as a reward for visiting. The liquid is siphoned with their straw-like glossa and stored in a special organ called the honey stomach, or crop. We depend on bees to make much of our food. One third of what we eat comes from this pollination!

KWL Strategy: What I Know, what I Want to learn and what I did LearnThe KWL strategy is a great way of getting students oriented to the lesson, forming individual goals within the group and recapping the lesson. It may be helpful to use a chalkboard or white board to make 3 columns for each component to gather and organize questions and ideas.

• The K component serves the purpose of brainstorming. Have the students work as a group (or individually followed by sharing) to drum up what they already know about bees and their anatomy. Questions listed below can be used to guide students through this process.

• The W component questions provide the students with lesson goals. They can also give each student the opportunity to come up with their own inquiries and concentrate on something they are curious about. Students can write these questions down and find the answers before, during or after the lesson.

• The L component questions help the students synthesize the lesson and the information covered. Questions may be completed in writing or discussed as a group.

K Component Questions:• What comes to mind when you think of bees?• What bee body parts can you think of?• Why are bees important?• Where do bees live?• What do bees eat?• Why do flowers need bees?• What attracts bees to flowers?• Can all bees sting?• What happens to a bee after it stings?• What are the stages of metamorphosis in bees?• How would the disappearance of bees affect us?

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W Component Questions:• What body parts are associated with a bee’s head, thorax and abdomen• What structure is associated with each sense (taste, touch, smell, sight, hearing) in a bee?• How is a bee’s body adapted for pollination?

L Component Questions:• What are some different parts of a bee?• What are the three body regions of an adult bee and what functions do they serve?• What is the life cycle of a bee (the four stages of metamorphosis)?• What behaviors and structures make bees good pollinators?

T-ChartThe T-Chart is a simple pre-assessment method to determine what information students already know about bees, and whether it is factual or biased. This method asks two questions to the class and encourages group discussion. Answers can be pooled in two columns on a blackboard. An example for this lesson is What do you know about a bee’s anatomy?and What questions do you have about their anatomy?

If any incorrect ideas are presented while answering What do you know about bees?, write them down anyway and revisit them at a later time. Let students go back over the Column 1 list and determine if the ‘facts’ are correct.

Student Assessment and Lesson WorksheetsAssessments have been designed to meet the National Science Assessment Standards. It is left to the instructor’s discretion which of these techniques to use and how to weigh them as part of a total assessment. The following assessments have been provided below, followed by answer keys, where appropriate:! Lab report: 5 page lab report with questions, calculations, etc. in student packet (pp.1-5)! Essays: 10 essay questions to choose from; provided in student packet (p. 6)! Crossword puzzle: Structure and function terms in student packet (p.7), answer key below! Quiz: Matching and diagram labeling in student packet (p. 8), answer key below! L component questions: use for writing or discussion purposes.

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Structure and Function Crossword Puzzle Answer Key

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Note: You can use a different program named Crossword Weaver® to print a nicer copy ofthis puzzle, one that doesn't look like a web page. This software program gives you muchgreater control over how the puzzle looks, lets you export your puzzle to other software,publish it interactively on the Web or as a PDF file. Check it out for free by downloading thedemo from www.CrosswordWeaver.com. Purchasing converts the demo into the fullprogram.

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www.crosswordpuzzle.com

http://www.crosswordpuzzle.com

http://www.crosswordpuzzle.com

Quiz Answer Key

Directions: Match the structure with the correct description of its function.

Structure! ! FunctionOcelli! ! ! Pollen storage (corbicula)Antenna ! ! Detection of presence and absence of light (ocelli)Thorax!! ! Defense of the hive (stinger)Corbicula! ! The senses of smell and taste (antenna)Stinger!! ! Contains all structure needed for locomotion/movement (thorax)

Directions: Label the bee illustration below with the following terms: Abdomen, Antenna, Compound eye, Ocelli, Tarsi, Thorax, Veins, Forewing, Hindwing, and Head. Next, add the following structures to the illustration: Glossa, Hamuli, Stinger, Corbicula and Ommatidia.

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Antenna OcelliTarsi

Compound eye

Veins

Forewing

Hindwing

Head

Abdomen

Thorax

L. I. Lynch

Anatomy Dissection Directions1. Provide each student with one External Anatomy of the Adult Honey Bee Lab Report.2. Provide each pair of students with one worker bee. Students can keep their bee in a Petri dish or

other small holding container to keep it safe from falling, damage and getting lost.3. As students move through the lab report, they may want to check off what structures they have

found on the Anatomy Checklist section (page 5) of their lab reports. They can fill in the functions as they go or after class.

4. Students should hold their bee with forceps by one of the legs. Let them study the general appearance of the specimen and complete Sections 1 & 2 of their lab report.

5. Using forceps, the students should carefully remove one antenna from the head of their specimen. If possible, they should make a wet mount. Alternatively, they can carefully dip it into a drop of water to wet one side and place it onto a slide and let it dry. Let them study the antenna and then complete Section 3 of their lab report.

6. Holding their specimen with forceps, let them study the mouth and face of their specimen and then complete Section 4 of their lab report.

7. Using forceps, students should carefully remove one foreleg, one middle leg and one hind leg. They should grasp the leg as closely to the thorax as possible. With the other forcep holding the bee’s body, a gentle pull will release the leg.They shold then place the legs on a glass slide and view them under the microscope. Let them study the various structures of the legs and then complete Section 5 of their lab report.

8. Using forceps, the students should carefully remove one forewing and one hindwing from the specimen in the same manner as used for the legs. The wings can be carefully placed on a microscope slide. It is recommended that students prepare a wet mount but dipping them in water will help the wings stick to a glass slide and help prevent them from being blown away. The wings and antenna may be placed on the same microscope slide. Let them study the wings and then complete Section 6 of their lab report.

9. Holding their specimen with forceps, let the students study all sides of their specimen’s abdomen and then complete Section 7 of their lab report.

10.If time allows, have students look for images of queen and drone honey bees on line (or if specimens are available, let them view them for comparison) and then complete the Caste comparison table (page 4) of their lab report.!

VocabularyAbdomen: the last (hind) body segment of an insect.Antenna (antennae, plural): a sensory appendage of the head used for taste, smell and hearing.Antenna cleaner: a notched groove in between two segments of the forelegs used to clean the antennae.Coevolution: the joint evolution of two or more species in which their behavior and/or anatomy changes to benefit one another.Complete metamorphosis: a four stage life cycle seen in most insects, including bees, in which the larvae have a radically different appearance from adults. Larvae enter a non-feeding pupal stage during which metamorphosis occurs and adult characteristics (such as wings) are developed.Compound eyes: the large eyes of a bee composed of many small eye facets called ommatidia.Corbicula (corbiculae, plural): a pollen basket made of long coarse hairs located on the hind legs of a bee; stores pollen during flight.Crop: a special storage organ of the digestion system that holds nectar, honey and water for transport. Also called a honey stomach.Defensive behavior: a behavior used to avoid predation or harm.Egg: the first, white, oval-shaped stage in the bee life cycle.

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Exoskeleton: the hard, outer covering of insects; an external skeleton.Femur: the third segment of the leg.Glossa: the tongue of a bee; used to siphon liquids.Hamuli: small hooks located on the upper margin of the hind wings that hold the fore- and hind wings together during flight.Honey stomach: see Crop.Invertebrate: an animal that does not have a backbone.Johnston organ: a tiny organ located on the second antennal segment that detects flight speed.Larva (larvae, plural): the second, worm-like stage of the bee life cycle.Locomotion: the act of moving.Mandibles: the jaws of the bee, used for chewing.Maxillae: the second pair of chewing mouthparts found beneath the mandibles.Metamorphosis: structural changes that occur through a bee’s developmental stages.Nectar: the sweet, sugary liquid in a flower’s center that attracts pollinators.Ocellus (ocelli, plural): simple eye that is light-sensitive; bees have three such eyes.Ommatidium (ommatidia, plural): an eye facet that, with hundreds of others, comprises the compound eye of an insect.Pheromone: a chemical produced by bees to communicate with one another.Pollen: the powder seen in a flower’s center that must be passed between flowers in order to produce seeds.Pollen basket:the pollen collecting structure of bees made of stiff hairs.Pollen brush: a brush like structure on the hind leg that removes and collects pollen from the body.Pollen press: a toothed area between two segments of the hind leg used to compact pollen collected by the pollen brush.Pollination: the transfer of pollen between plants.Pollinator: an animal that passes pollen from male to female flower parts of the same flower or other flowers of the same species.Pretarsus (pretarsi, plural): the foot of a bee.Proboscis: a general term for the bee’s elongated mouthparts.Pupa (pupae, plural): the third, non-feeding stage in the bee life cycle.Sense hairs: small sensory filaments covering the body that are especially concentrated around the antennae.Spiracles: small, openings in the exoskeleton that allow the entrance and exit of air into the bee’s body.Stigma: a female part of a flower that is sticky to capture pollen.Stinger: a sharp, pointed appendage on the tip of a female bee’s abdomen that is used defensively to inject venom.Tarsi: the feet of the bee.Thorax: the middle body section of an insect where wings and legs are attached.Tibia: the fourth segment of the bee’s leg; the tibia of the hind leg has the corbicula.Veins: tubular and sclerotized tubules that branch throughout the wings, providing strength and supplying blood and nerves.Ventral surface: the “belly” side of an organism.Wax glands: glands located on ventral surface of the abdomen of young bees that produce the wax used to build wax comb.Wings (hind and fore): the flight appendages of bees; bees have a total of four wings.Wing cell: an area of the wing membrane that is enclosed (fully or partially) by veins.

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References & Further ReadingAlford, D. V. 1978. The Life of the Bumblebee.Hebden Bridge, United Kingdom: Northern Bee Books.

Dade, Henry A. 1962. Anatomy and Dissection of the Honeybee. Cardiff, United Kingdom: International Bee Research Association.

Center for Science, Mathematics, and Engineering Education. 1996. National Science Education Standards. Washington, D.C.: National Academy Press.

Gould, James L. and Gould, Carol G. 1988. The Honey Bee. New York, New York: W. H. Freeman & Co.

Hassard, Jack. 2000. Science as Inquiry: Active Learning, Project-Based, Web-Assisted, and Active Assessment Strategies to Enhance Student Learning. Culver City, California: Good Year Books.

Tautz, Jurgen. 2008. The Buzz about Bees: Biology of a Superorganism. Berlin, Germany: Springer.

Xerces Society. 2011. Attracting Native Pollinators: Protecting North America’s Bees and Butterflies. North Adams, Massachusetts: Storey Publishing.

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