We’ve been hearing a lot about the New World Order lately. The term has many meanings, depending on what part of the earth is discussed. Whether countries themselves, the United Nations or the United States consider taking action when things get out of control, the goal is always the same, to establish order. The perennial questions are what kind is needed and how is it to be preserved. After all, even chaos (most dictionaries define this as “disorder”) mathematicians now tell us, has order.
How many have looked at the random movement of honey bees in a colony and seen only chaos? It is amazing that out of what at first glance appears to be random movement by thousands of individual insects, wonderful organizational patterns emerge. This confounded the ancients, who no doubt gave the credit to a panoply of gods. Researchers, using the tools of modern science, however, are constantly finding new clues about how order is established in a honey bee colony. That the source of much of it is from the queen is no surprise, but the details are often beyond our experience.
It is now definite that certain chemicals, called pheromones, regulate many of the activities of social insect societies. In “The Essence of Royalty: Honey Bee Queen Pheromone,” (American Scientist: Vol. 80, No. 4, pp. 374-385, July-August 1992), M. Winston and K. Slessor state that some 36 pheromones have been identified in honey bees. Those of the queen, called primer pheromones, have long been thought to control the colony. Studies suggest they suppress queen cell construction by the colony and also block ovarial development in worker bees. There is also evidence queen pheromones attract workers (and drones) and stimulate foraging.
Early research in this field first identified two chemical compounds, 9-keto-2- decenoic acid (9ODA) and 9-hydroxy-2-decenoic acid (9HDA), found in the mandibular glands of queens as possible candidates for queen pheromone. These, particularly the latter, were often referred to as “queen substance.” Although these compounds were active, the authors state that when synthesized, they did not fully duplicate the effects of mandibular gland extract.
It remained to discover that adding three more chemicals (two of completely different structure) made a pheromonal complex that was equivalent to mandibular gland extract. All the components are necessary for this royal essence to work; removing any one reduces activity by up to 50 percent. The component blend will vary with age. Virgin queens have practically none of these pheromones, only secreting the full array after being mated and laying eggs. Several other glands secrete chemicals that play a role in queen pheromonal communication.
A final part of the pheromonal puzzle concerned how the chemicals reached all workers in the colony. The bees in the royal retinue surrounding the queen transfer the pheromones from her to themselves and thence to their sisters. Two types of bees were identified by the authors : lickers and antennators. The former disperse most of the pheromone; why there are two kinds of workers in the retinue is a mystery. The comb wax also picks up some pheromone which is later transferred to other workers. The question of how the bees detect the pheromones remains unresolved.
Almost all the queen pheromone produced ends up internalized both in the queen’s and workers’ bodies. The route can be through either the mouth or the skin (cuticle). This internalization may be one reason the queen produces so much pheromone. It is suggested there might be a push-pull in worker-queen conflict. In order to escape the queen’s chemical control, workers quickly try to absorb and break down (catabolize) the regulating chemicals. At the same time, the queen attempts to manufacture more pheromones to increase her dominance. This is analogous with many families and societies that show a blend of cooperation and conflict, with some objectives in common, but individuals having their own goals as well.
Much of the dynamics in queen-worker conflict happens in swarming. Only when insufficient amount of pheromones are present will workers begin to rear queens. Given a queen that is constantly producing these controlling chemicals, the possibility exists for a reduction in pheromone only as colonies expand their population. According to the authors, a time is reached where there simply is not enough pheromone to go around, particularly if more and more is being internalized by greater numbers of workers.
The application of queen pheromones to control swarming is described further by Y. Lensky and P. Cassier in “Control of Swarming by Queen Bee Pheromones,” BeeScience, Vol. 2, No. 1, pp. 7-11, March, 1992. The authors contrast emergency or supersedure cells being constructed in the nest’s center (source of queen pheromones lost or very reduced) with swarm cells being built on the edges (queen pheromones not reaching the periphery). They determined a two-stage process in the latter process: (1) queen cups are constructed where a queen can lay an egg and (2) the cup with its egg is then transformed into a queen cell.
The authors confirm that as the worker population grows and nest congestion develops, the tendency to swarm increases. This is especially true when the queen’s movement is restricted. They go one step further, however, by concluding that another pheromone is acting together with chemicals from the mandibular gland to suppress queen rearing. This is an oily substance emitted from the queen’s feet that she leaves on the comb. The paper describes the structure of the gland that produces the queen’s footprint substance.
Although unable as yet to prevent swarming using pheromone application, the authors have developed a procedure calculated to decrease it. They have minimized the production of new queens and thus reduced swarming by (1) annual requeening, (2) increasing the volume of hives by adding supers in excess, 3) raising 7 to 8 brood frames from the brood nest into the supers above the queen excluders, (4) preventing overheating by providing additional openings to help ventilation and (5) providing a constant water supply in the bee yard. This technique takes into consideration most of what is known about the pheromonal order established by queen honey bees, but one always ready to be undermined by the workers in the absence of royalty.
ROYAL PHEROMONE: QMP TRIALS IN FRANCE
Although not necessarily apparent in insect population management, there is a quiet revolution taking place. This powerful movement seeks to replace use of broad spectrum insecticides with pheromones that are more focused and, therefore, more environmentally benign. This “pheromonal revolution” is the subject of European Notebook Number 12, published in several journals dedicated to beekeeping throughout the Continent.
According to the Notebook, news of this was carried to Europe by Dr. Mark Winston, now on the Faculty of Simon Fraser University, British Columbia. He barnstormed through France invited by ADAPI, INRA and the Méditerranean GRAPP with the message that apiculture will also be heavily influenced by this turn of events.
The first pheromone to be identified was isolated from moths in 1959, the Notebook quotes Dr. Winston. The following year, a royal pheromone was found in the queen honey bee called 9 oxo-2-decenoic acid, produced by the mandibular gland. Since then over thirty pheromones have been found in honey bees. Like many pheromones, the queen’s royal one has been found to have many constituents; as a consequence it is called queen mandibular pheromone (QMP), according to Dr. Winston. It also has several functions, including keeping worker bees from building queen cells, attracting drones during mating, and controlling swarming.
[Editor’s note: Via e-mail, Dr. Winston says he is not quite ready to characterize the use of pheromones in beekeeping as a true revolution. Instead, he takes a lower key approach, suggesting that this use is simply a management tool with possibilities in some situations. He also says there is evidence that QMP does not inhibit worker ovarial development, but rather brood pheromone is responsible.]
REVOLT IN THE BEEHIVE: GENETIC REBELLION BY WORKER BEES
The control of workers by the queen through royal pheromones may not be as complete as many text books would have us believe. This is not surprising. Any apiculturist knows that exceptions are the rule by which honey bees and beekeepers must live. Sciences et Avenir, Number 603, May 1997, published in Paris carries an article that appears to show this all too well. Called “Revolt in the Hive,” the article describes research done in Melbourne, Australia by B. Oldroyd, J.-M. Cornuet and A. Smolenski which surprises and delights.
It seems that a rebellion is carried on by worker honey bees in some colonies in the quest to make their own genetic contribution to the species. In spite of the queen’s royal pheromonal control, the article says, DNA study confirms that workers continually are laying eggs in colonies that have many drones. This gives credence to Dr. Winston’s doubts expressed elsewhere in this issue concerning inhibition of worker ovarial development.
To avoid detection by their sisters, these rebellious egg-layers have covered up their deeds by ensuring theirs are marked with royal pheromone, the article says. The authors further suggest that some workers have even compounded their crime by replacing royal eggs with their own! Such anarchy, the article concludes, carries a virus of its own perpetuation, the production of drones which pass the tendency on to other colonies through queens they mate with.