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Unformatted text preview: Lecture 7
Order: Isoptera Ants
Order: Hymenoptera Honey Bees
Order: Hymenoptera Lecture Questions
• What is meant by social behavior?
• Why are most social insects in just a
• What is eusociality and what kinds of
insects are eusocial?
• What role does chemistry play in
• What can humans learn from models of
social behavior taken from the insect
world? What is meant by social
•There are different levels of sociality in the insect world,
Individuals that provide parental care to their young
(subsocial) to eusocial (“truly social”) insects that form
( truly social )
• Characteristically, eusocial insects:
•live in colonies formed by large work forces.
•exhibit division of labor with cooperation between
•may have specialized groups or “castes” with
particular skills and duties. 1 Five Levels of Social Behavior in Insects
Type Insect SubSub-social Cockroaches, beetles, bees, wasps Communal Bees, wasps QuasiQuasi-social Bees, wasps SemiSemi-social Bees, wasps Eusocial Honeybees, ants, termites, some
thrips and aphids Five Levels of Social Behavior in Insects
Type Behavior Eusocial •Individuals cooperate to build a nest.
•Only a few individuals have functional
ovaries and can mate and reproduce.
•A strict caste system is evident.
•Non-reproductive individuals feed and care
Nonfor offspring produced by reproductive
•Overlapping generations are present
together in the nest. Castes in the Honey Bee Hive
•Queen Bee (the single female reproductive)
•Drones (male reproductives that leave the hive to
mate with virgin queens and do not return). •Workers (All Female)
•Guards and Undertakers
•Pollen Collectors and Nectar Collectors
•Field foragers 2 Castes in the Termite Colony
•Queen (the single female reproductive)
•King (the single male reproductive •Workers (Male and Female)
•Attendants for the Queen.
•Soldiers The Role of Chemistry
•Caste Determination in the Honey Bee
•Queen exerts chemical dominance by secreting queen
substance from glands in her head. Passed to workers
grooming her who pass it to other workers.
•Queens live for approximately 5 years. As she ages, she
produces less queen substance. Workers react by rearing
new queens and swarming.
•Immatures destined to become queens are exclusively fed
royal jelly or bee milk secreted by glands in head of the
worker. Larvae destined to be workers receive royal jelly for
only 3 days. The Role of Chemistry
•Caste determination in the termites
•Chemical communications between the
queen and her attendants provide the
queen with a full report on the state of
her colony. She lays eggs of the right
type to fill the needs of the colony. The
precise mechanisms are unknown. 3 The Role of Chemistry
•Communication is one of the greatest keys to
the evolutionary success of eusocial insects.
•Chemical communication is widely used by all
eusocial insects to provide diverse information. Architecture and
Hexagons— • Storage facilities: honey, pollen, brood
• Mapping tools: Waggle Dance Why a Hexagon?
– A hexagon uses less wax to create a
shape with maximum volume
– Hexagonal tubes use 18% less wax
than triangular tubes, 7% less than
square tubes • Maximizes use of space (compare
to circular tubes) 4 A Bee-Space
• Honey bees consistently build their
honeycombs 1 and 3/8 of an inch
apart. (Honeycomb at 1”, 3/8” as a
• Bee-space = in spaces greater than
Bee3/8” bees try to build more
honeycomb, in spaces less than ¼”
bees close the space with propolis.
propolis. The Birth of the Domesticated
Bee Hive The Langstroth hive:
Took advantage of the
concept of the bee
space with hanging
honeycombs with a 3/8
between. Design is
used in most modern
bee hives. 5 The Honey Bee Waggle Dance
Combining Sensory Cues for
Communication-Communication-The importance of the Honeycomb The Waggle Dance
•THE ROUND DANCE = food is near
(within 25 m of the hive). No
•THE WAGGLE DANCE = food further
away (more than 100 m). Waggle
dance = a flattened figure-of-eight.
figure-of•Squeaks, buzzing and waggling attract
ste e s
•LENGTH of the straight center run
indicates distance of the food
•The ANGLE provides directions.
•The number of honey combs
passed = means of measurement.
•Samples are given and floral
fragrances shared to give info on
quality (chemical). Paper Wasps: On the way to sociality 6 A Closer Look At Nest Use Larva Egg 7 The Hornet Nest, Yet a Different Design Ants as Architects: Aerial Evidence Small Fire Ant Mound Red Ant Nest in Forest Ants as Architects: Tunnels and Galleries The Queen’s Chamber 8 Argentine Ants
Why can they have such large colonies? Altruism, Consciousness, Models for
Human Behavior and the Social
• Basis for altruism—
– Genetic (Kin Selection)
– Group Selection • Consciousness
• Models for coordinated human activity
– Emergency Response
– Swarm Behavior 9 ...
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- Fall '08