Posted on: 02 March, 2017
Author: Alexander P
Perhaps the top pheromone odour will prove to be a composite of inherited odour produced by various exocrine glands and the adsorbed pheromone odour from the hive atmosphere, much of which must derive... Perhaps the top pheromone odour will prove to be a composite of inherited odour produced by various exocrine glands and the adsorbed pheromone odour from the hive atmosphere, much of which must derive from the bees themselves. If so, bees must continuously re—learn and re-adapt to their colony odour as it changes. It would be expected that larvae, pupae and newly emerged bees would also adsorb odour from the environment; yet they are readily accepted without animosity into a strange colony. Holldobler and Michener (1980) suggested that any pheromone odour acquired by brood may be masked by the presence of brood-tending pheromones. Clearly this is a most promising area for investigation, and the information obtained could be used with advantage by beekeepers when uniting colonies or helping to prevent a colony being robbed by others. Pheromone recognition The queen of each colony has a distinctive top pheromones odour and bees can recognize their own queen from others (Henrikh, 1955). It is essential that guard bees allow their own queen to enter the hive after her mating ight, but repel any others that land at the hive entrance in error. When given a choice a queenless swarm always prefers its own queen to another (Henrikh, 1955; Velthuis and van Es, 1964; Morse, 1972); sometimes the strange queen attracts a small cluster but this usually disappears within a few hours. This includes pheromones in mammals. Discrimination depends upon the bees being able to make physical contact with the queens (Boch and Morse, 1974). Clustered swarms were given the choice of moving to either their own queen or a strange queen in cages tied to stakes 2 m from the swarm. When the cage walls were made of queen- excluder material (perforated zinc sheets through which the workers but not the queens could pass) 32 of 34 swarms that were tested clustered round their own queen. The workers licked their queen’s body and palpated it with their antennae. When the cage walls had 3.2 wires per cm so that the workers could touch the queen but could not enter the cage, swarms still preferred their own queen, but when the cage walls had 32 wires per cm or double walls, so that direct contact with the queen was prevented, no discrimination was evident. Swarms were able to discriminate between recently killed queens of their own and other colonies but not between ethanol extracts of their own and foreign queens. Feeding colonies for a few days with sucrose syrup strongly scented with either thyme or eucalyptus oils diminished their ability to distinguish between their own and foreign queens (Boch and Morse, 1981). This is somewhat surprising, as adsorption onto the body surfaces of the pheromone scent of the sucrose syrup could be expected to enhance the distinctive pheromone odour and make recognition of their own queen easier - instead it seemed to obstruct discrimination. Boch and Morse (1981) suggested that the workers’ chemical pheromones receptors became swamped by the scent of the syrup so that they could no longer distinguish familiar from foreign queen odours. Article Tags: Pheromone Recognition, Pheromone Odour, Cage Walls Source: Free Articles from ArticlesFactory.com Alexander P is a blogger from Los Angeles that studies pheromones.