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My Pheromones Blog

To Produce Pheromones

The reluctance of colonies to produce pheromones in early spring when their worker populations are relatively small, and the reluctance of small colonies to build drone comb at any time, suggest that the amount of queen pheromone is sufficient to inhibit drone cell production in small colonies but as a colony becomes larger it is no longer sufficient. Early in the season the small amount of worker brood present in a colony produces insufflcient pheromone to counteract the queen pheromone but as the amount of worker brood increases there is also an increase in the proportion of drone brood reared.

Toward the end of the summer, as the amount of worker brood reared diminishes, the queen’s inhibitory pheromone reasserts its influence. Drone cell production, drone rearing and the tolerance of drones by workers is encouraged in the presence of failing queens with a diminished output of pheromones. Furthermore, drone comb, drone brood and adult drones also appear to produce inhibitory pheromone; this would account for the feed- back mechanism whereby when sufficient drone comb, drone brood or adult drones are present further production is inhibited. Learn about pheromones at

A steady diminution in the amount of forage available would cause a corresponding reduction in the amount of worker brood reared and hence of the tolerance of adult drones. It is more difficult to explain the release of worker hostility to drones following an abrupt cessation of foraging. Perhaps foragers are basically hostile to drone odour but in the presence of ample forage this underlying hostility is repressed; an abrupt end to foraging leaves numerous idle foragers who are ready to defend their colony against intruders with hostile odours (page 102). Furthermore, foragers are less likely than nest bees to receive the relevant pheromone emanating from worker brood according to

, which could help to explain why older drones may be attacked by unemployed foragers while younger drones of the same colony are being fed by the workers. This hypothesis needs to be tested experimentally by varying the relative amounts of the queen and worker brood pheromones present.

Pheromone applications

Many beekeepers regard drone production as wasteful and attempt to avoid having any drone comb in the brood area of colonies. Because the amount of drone comb in a colony overrides the effect of the time of year in determining whether more is built, presumably through the amount of pheromone produced, using drone comb in the honey storage supers should prevent drone comb being built in the brood area. However, although the absence of pollen in the drone comb provided would be an additional bonus, bees do not favour drone comb for honey storage — so the use of drone comb in the honey storage supers of beehives is of questionable value. If the appropriate pheromone of drone comb could be isolated and synthesized it might be useful in inhibiting drone production in colonies that could also be kept free of drone comb.

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Darchen et al., (1957) stated that no drones appeared in multi-queen colonies. If the role of queen pheromone in inhibiting drone cell production is verified it should eventually be possible to increase the amount available per worker by introducing additional queens (page 66) or synthetic queen pheromone.

Drones from Africanized colonies in South and Central America readily join and adopt colonies of European bees, whereas the reverse occurs much less often. As a result there is a deficit of drones in Africanized colonies and they are encouraged to produce more, but the influx of Africanized drones into European colonies inhibits drone production. The Africanized colonies therefore have an important reproductive advantage. Where appropriate, efforts could be made to exclude Africanized drones from European colonies and destroy them (Rinderer et al. , 1985).