Regulation of Pheromones

Zmarlecki and Morse (1964) found that drone populations remained normal in two colonies that were headed for eleven months by queens whose pheromone glands had been extirpated.

Pheromones also influences the amount of drone comb built. For the first few days after combs had been removed from colonies only worker cells were built. The queens were then removed which greatly diminished the rate of cell building but still all those built were worker cells. Each colony was then given a comb of worker larvae and during the next few days all built much drone comb (Free, 1967a).

However, because on each comb that had been introduced a few of the female pheromones were being reared as queens, further experiments are needed to compare the effects of queen and worker larvae on drone cell production. The influence of a virgin queen also needs to be investigated.

Darchen (1968) confirmed the inhibiting effect of a queen on drone cell building. The half of a colony that retained its trail pheromones built only worker comb while the queenless half built drone comb. He obtained evidence that the presence of worker pupae encourages drone cell construction. Queenless colonies fed sucrose syrup built drone cells only when they had combs containing worker pupae, but when they had no worker brood they changed to building worker comb. Learn about pheromones at Pherlure |

The amount of release pheromones produced also depends on the amount already present. It is possible to reduce the number of drone cells built in a colony by adding drone comb, or to increase drone cell construction by removing all existing drone comb (Free, 1967a). It seems likely that an identifying pheromone is incorporated into drone or worker comb as it is built (page 71).  

Experiments are needed to determine whether the odour alone emanating from drone comb has an inhibitory effect. 

Drone pheromone production

The amount of pheromones and the number of adult drones in a colony is also correlated positively with the size of its worker population (Mathis, 1947). Colonies with little brood have only a small proportion of drone brood or none; colonies with much brood tend to have the greatest proportion of drone brood (Free and Williams, 1975).

Although in England a large percentage of eggs are laid in drone cells before the end of April, few are reared, and the proportion of drone brood in a colony is at its maximum in May and June (Free and Williams, 1975). Queen cells are produced most abundantly during late June and early July, but within a colony there is no clear evidence of correlation between the dates of drone brood and queen cell production (Simpson, 1957; Allen, 1965b).

Furthermore, there is no evidence that drone rearing releases queen pheromone production.