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Encyclopedia > Pheromones
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Fanning honeybee exposes Nasonov gland (white-at tip of abdomen) releasing pheromone to entice swarm into an empty hive

A pheromone is any chemical produced by a living organism that transmits a message to other members of the same species. There are alarm pheromones, food trail pheromones, sex pheromones, and many others. Their use among insects has been particularly well documented, although many vertebrates also communicate using pheromones. Their use by humans is controversial.


Insect pheromones of pest species, such as the Japanese beetle and the gypsy moth, can be used to trap them or to create confusion so that the pests do not lay eggs on crops.


In mammals and reptiles, pheromones may be detected by the vomeronasal organ, or Jacobson's organ, which lies between the nose and mouth, although some are detected by the nose.


Human pheromones

Pheromones are a popular device in fiction, including the novel Jitterbug Perfume by Tom Robbins and the film Love Potion Number Nine. They were also mentioned in an episode of Wolfgang Petersen's The Agency.


Some commercially-available substances are advertised using claims that the products contain sex pheromones and can act as an aphrodisiac. These claims often lack credence due to an excessive marketing of pheromones by unsolicited e-mail, and their effectiveness has not been demonstrated scientifically.


Nevertheless, a few well-controlled scientific studies have been published demonstrating that humans may use pheromones in some circumstances. The best-studied case involves the synchronization of menstrual cycles among women based on odor cues (by Martha McClintock, Professor of Psychology at the University of Chicago), she said that there is two types of pheromone involved: "One, produced prior to ovulation, shortens the ovarian cycle, and the second, produced just at ovulation, lengthens the cycle". Other studies have suggested that people can use odor cues to select mates who are not closely related to themselves.


Pheromones in humans are believed to be produced by the apocrine glands. These glands become functional after reaching puberty, which could explain why most people become attracted to the opposite sex at that time. Pheromones could also be the reason why we feel that instant attraction, or dislike when we first meet someone.


See also


  Results from FactBites:
 
Pheromones (582 words)
Pheromones are chemicals emitted by living organisms to send messages to individuals of the same species.
Bombykol, the sex pheromone of the silkmoth, was first synthesized in 1959.
During the past 40 years, pheromones of hundreds of insect species have been chemically elucidated, including the sex pheromone of the codling moth.
PHEROMONES (2489 words)
The use of pheromones in control is similar to methods used for monitoring but involves mechanisms which either kill the insect directly on contact with the trap, or serve to disseminate a chemical or pathogen which later renders them and, depending on the method others they contact, dead.
Pheromones are chemicals which when released result in either attracting or dispersing insects of the same species, that is to say they are intraspecific.
Aggregation pheromones which may or may not be produced by either sex to congregate the species for feeding or reproduction, and alarm pheromones that serve to rapidly disperse a group of insects usually as a response to predation (Nordlund 1981).
  More results at FactBites »


 

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