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Analysis of Honeybee Aggression By Dylan Voeller and James Nieh I. Principles introduced in this
exercise A. Aggression: how they
attack B. Defender's
perspective: what to attack D. Differences
between European honeybees and Africanized honeybees C. Results of aggression II. Introduction Honeybees are famous
for many things, including their ability to inflict painful stings. This exercise focuses on honeybee
aggression and uses a video demonstration of honeybee attacks and the kinds
of things that honeybees like to attack.
Perhaps this can help you learn what to avoid in the future! Although the video and exercise focuses on
the commonly found European honeybee, the behavior of Africanized honeybees
is quite similar, except that their aggressive response is, as a group, more
intense. General honeybee aggression Honeybees generally
attack only to defend their colony, but will also attack if they are
seriously disturbed outside the nest.
Common sources of attack stimulus for honeybees include alarm
pheromone, vibrations, carbon dioxide, hair, and dark colors (Crane 1990). This makes sense
because mammals, which are common predators of bees, are usually hairy, dark
colored, and exhale carbon dioxide. If
you think about this you will realize that bees are drawn towards attacking
sensitive areas around the head of a common predator. Stinging is the
ultimate final act of a honeybee because soon after, she will die. First the bee becomes alerted; she takes on
a guarding stance and protrudes the sting, which recruits other bees by
releasing alarm pheromone. Secondly,
the bee will search for the source of stimulus and orient towards it. Finally she will attack; emitting a high
pitched buzz and making body thrusts towards the source of disturbance. In such a defense response, honeybees
rarely pursue stimuli for long distances (although Africanized bees can
pursue victims for hundreds of meters.
If a sting does occur, the bee will die soon after stinging because
the sting is left behind and the bee disembowels itself in flying away. Once the bee’s sting is inside a victim, it
pumps out more venom and emits alarm pheromones. During this time, the stinging bee will
spend its dying moments distracting its victim by flying around its head as
if it were going to sting again. Africanized honeybees Africanized honeybee
venom is not more painful or voluminous than normal honeybee venom, its just that many more bees will sting! This is because Africanized honeybees are
very sensitive to alarm pheromone (the odors, smelling a bit like banana,
which foragers release from their sting gland and glands located in the head
when they are alarmed) and produce much more of it than temperate
honeybees. The threshold for stinging
response in Africanized honeybees is also much lower; only a minor
disturbance such as a slight motion, vibration, or odor is needed. A study by Collins (1985) showed
Africanized honeybees respond 2.4 times faster to alarm pheromone and about
30 times as fast to a moving target! Once Africanized bees have been stimulated,
they are also much more likely to respond in group attacks. During such attacks they will sting
anything in sight that is moving and may pursue a source of disturbance for
up to a kilometer (Winston 1992). The rapid defense
response of Africanized honeybees is most likely a result of adaptation to
life in tropical climates, where there is a higher rate of predator attacks
on colonies. These higher attack rates
favor the evolution of rapid colony defense, since successful nest defenders
are able to survive and produce more offspring than those that are killed off
by a predator, such as a badger who is hungry for honey. The biology of
Africanized bees, including their higher level of aggressiveness, is thought
to play a role in their successful invasion throughout the III. Materials & Methods A.
Open and view
the first bee attack video. B.
What are the
bees attacking? C.
What happens
when a bee stings? D.
How do other
bees react to the odor of alarm pheromone? E.
Open the video
of bees stinging a cotton ball. Does
this response decrease with distance? F.
Are there any
there any other stinging preferences? Color, hairiness? IV.
Sample
Results (Insert
screenshots of what bees like to sting) V. Sample Discussion Questions A.
What
stimulated the bees to attack? The
bees were agitated and reacted to alarm pheromone
B.
Once stimulated, what did the
attackers focus on? Dark
hairy objects C.
Why might
the bees show such an attack preference? Common
mammal predators are often dark colored and hairy. Sensitive areas
such as the nose, mouth, and ears are also dark.
D.
Have you ever seen a bee attack
before or been attacked? If so, what do you think stimulated the bee’s
response? E.
What are
some strategies for avoiding Africanized bee attacks? Keep
away from nesting areas and be alert when active in outdoor areas
where bees and their nests are common. Close off any openings in and around your
home that might make a good nest site if Africanized bees are known
to inhabit your area. F. Why
changes might be caused by Africanized bees introduced into an ecosystem in
which they weren’t formerly present? Africanized bees could outcompete native bees with their
aggressive behavior and faster rates of reproduction. However, there is controversy about whether
Africanized bees truly have had a significant impact on native bee
populations. If they do have such an impact, nest sites and available
food may become dominated causing declines or even extinctions in
native bee populations. This
could lead to declines, extinctions, and other changes in the plant
communities that depend on bees for their reproduction and, in turn,
changes in the animal populations that depend on those plants for
survival. VI. Sample Conclusions
Collins, A.M., 1985.
Africanized honeybees in the Third
International Conference on Apiculture in Tropical Climates, International
Bee Research Association: 117-122. Crane, E., 1990. Bees
and beekeeping: science, practice, and world resources. York,
Hunt, G.J., Guzman-Novoa,
E., Fondrk, M.K., Page, R.E., 1998. Quantitative
trait loci for honey bee stinging behavior and body size. Genetics 148: 1203-1213. Winston, M.L., 1992. Killer bees: the Africanized honey bee in
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