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Pheromones in humans and insects

This article is about the use of pheromones in humans and insects. Colonies of about 5000 bees the queen and brood proved to have similar inhibitory pheromone releasers, but the presence of both did not have a greater effect than either on its own. Jay also divided queenless colonies by a screen (single or double) into two parts ; one part contained brood, the other part did not but its bees were of course exposed through the screen to the odour of brood. Pheromone development in the parts without brood was much greater than in the part with brood. However, it was less than in equivalent queenless and broodless colonies which were not subjected to the odour of pheromones according to

Therefore, it is apparent that nearness to or contact with brood has the greatest pheromone inhibitory effect, but the odour alone has some influence. The brood pheromone that stimulates foraging has a similar mode of action. Unfortunately no difference was apparent from using a double or a single screen. Probably this was because bees on the two sides of the screen make little attempt to pheromonaly contact each other. It is difficult in this type of experiment to know the amount of contact that has occurred through the screen and consequently the results are difficult to interpret. Learn about pheromones at

The volatile pheromone scent from the brood (which has some inhibitory power) does not appear to emanate from brood by-products such as faeces, or from cast skins and cocoons left in vacated cells.

Thus, a high incidence of ovary development can occur on old brood combs in queenless, broodless colonies and there is no difference in the extent of worker ovary development in colonies transferred to new comb or to old comb indicating that the inhibiting material is almost certainly a pheromone produced by the brood itself. Kubisova and Haslbachova provided caged bees with ethanol or acetone extracts of worker larvae in honey, on dead worker bees or on polystyrene blocks. All methods, but especially the first, helped suppress worker ovary development. In subsequent experiments Kubisovai et al. demonstrated that those fractions of dichloromethane extracts that contained acids or mixtures of acids and steroids had the greater inhibitory effect of pheromones from

The brood pheromone concerned could be the same as the brood recognition pheromone. Whereas brood pheromone inhibits ovary development it is probably necessary to stimulate development of the hypopharangeal glands (which produce brood food) of young bees; it seems to be necessary for the bees to make contact with the brood, the odour alone of the brood being insufficient (Free, 1961a). Lack of inhibitory effect of (E)-9-oxo-2-decenoic acid on queens. The ovaries of a queen honeybee develop normally despite the presence of a high concentration of 9-ODA in her mandibular glands and ample brood pheromone in her colony. Pain and Barbier (1981) were unable to detect pheromones.

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