oe has been teaching me a little bit about pheromones used by bees. The pheromones of the honey bee are mixtures of chemical substances released by individual bees into the hive or environment that cause changes in the physiology and behaviour of other bees. Honey bees have one of the most complex pheromonal communication systems found in nature, possessing 15 known glands that produce an array of compounds. These chemical messengers are secreted by a queen, drone, worker bee or laying worker bee to elicit a response in other bees. The chemical messages are received by the bee’s antenna and other body parts. They are produced as a volatile or non-volatile liquid and transmitted by direct contact as a liquid or vapor.
Above, you see my brother Joe checking a hive without protective gloves on! He has recently started working for the bee research team at the U of Mn where they are pretty hard core. The theory is if you don’t wear gloves you will move slower and more carefully, alarming the bees less, and are less likely to accidentally squish a bee. When a bee is squished, it releases an alarm pheromone which tells other bees to sting or charge.
Two main alarm pheromones have been identified in honeybee workers. One is released by the Koschevnikov gland, near the sting shaft, and consists of more than 40 chemical compounds. It appears to be the least specific of all pheromones. Alarm pheromones are released when a bee stings another animal, and attract other bees to the location and causes the other bees to behave defensively, i.e. sting or charge. The alarm pheromone emitted when a bee stings another animal smells like bananas. Beekeepers use smoke to mask the bees’ alarm pheromone, and some beekeepers believe you shouldn’t eat bananas before you check a hive to minimize their defensive behavior.
Another of the many pheromones used by bees is called the Nasonov/Nasanov pheromone. It is released by worker bees to orient returning forager bees back to the colony. To broadcast this scent, bees raise their abdomens, which contain the Nasonov glands, and fan their wings vigorously. Here’s a couple of our bees calling their brethren home at the entrance to their hive because of the disruption of us checking on the health of the hive:
Bees use this pheromone to find the entrance to their colony or hive, and they release them on flowers so other bees know which flowers have nectar.
Beekeepers attempt to attract a honey bee swarm to an unoccupied hive or a swarm-catching box by using a synthetic mimic of the Nasonov pheromone. Synthetically produced Nasonov consists of citral and geraniol in a 2:1 ratio. Citral is found in lemongrass, lemon and lime essential oil. By itself or combined with geronial, which is found in rose, lemon and geranium oils, citral has a powerful effect on bees.
Beekeepers suggest mixing lemongrass essential oil with geranium oil in a 2 to 1 ratio to mimic Nasonov and attract swarms. But some have had success with just lemongrass oil. Balking at the cost of geranium oil, my brother Joe, bought some lemongrass oil, put a few drops on a cotton ball and placed it near the entrance in his vacant hives, hoping to get lucky and acquire a swarm.
Beekeepers have this old rhyme concerning catching ‘free swarms’ :A swarm of bees in May
Is worth a load of hay;
A swarm of bees in June
Is worth a silver spoon;
A swarm of bees in July
Is not worth a fly.