The honey bee society cannot function without effective communication. Most honey bee communication occurs by smell and taste. The intricate system of chemical messengers are termed hormones and pheromones. A pheromone is a chemical secreted outside by an individual that when received by another individual of the same species results in a specific response such as a behavior. A pheromone differs from a hormone in that it passes from one individual to another.
Contents |
Queen Pheromones
One of the most active and vital chemical communication pheromones in the bee society is the mandibular gland secretion of the queen. The term “queen substance,” has persisted as the name of this mandibular gland secretion. Chemically it is very diverse with at least 17 major components; 5 of these compounds are: 9-oxo-2- decenoic acid (9ODA) + cis & trans 9 hydroxydec-2-enoic acid (9HDA) + methyl-p-hydroxybenzoate (HOB) and 4-hydroxy-3-methoxyphenylethanol (HVA). Newly emerged queens have little of the pheromone but by the sixth day the mandibular glands can produce enough chemical to enable the queen to attract drones for mating. Mature queens secrete double the amount and do so daily.
The chemicals are dispersed over the body of the queen as she is groomed by workers. Workers pick up the pheromone by antennal contact with the queen and share it with each other in the behavior of food transmission. When the queen is removed from her hive, worker bees become agitated within one hour and begin behaviors of queen replacement within four hours of her absence.
Queen substance is the pheromone responsible for the following behaviors:
- Inhibition in rearing of replacement queens
- Sex attraction
- Swarm stabilization
- Queen retinue behavior
- Stimulation of foraging and brood rearing.
Alarm Communication
Alarm pheromones are widely distributed in social insects. Honey bees have two different alarm pheromones, one from each end of the body. The mandibular glands of workers produce 2-heptanone and one of the glands of the sting produces isopentyl acetate. The sting pheromone is better known and is the major alarm chemical.
The chemical released when a bee stings, isopentyl acetate, is absent in newly emerged workers whereas bees 15+ days of age have one to five mg. There are several other components of the gland such as acetates and alcohols and they may work in conjunction with isopentyl acetate. Actual stinging or defensive behavior is correlated with isopentyl acetate. Defensive behaviors range from alerting to flying (buzzing); if disturbance persists stinging is the last response. Bees display a faster reaction time and more concentrated defensiveness upon perception of the alarm pheromone. Generally, bees will respond to alarm pheromone only at or near the colony, not in the field. Smoke in some way masks the pheromone.
The second alarm pheromone, 2-heptanone, is produced in worker mandibular glands. It, like isopentyl acetate, is absent in newly emerged workers but is present by foraging age. Bees respond to 2-heptanone at the nest entrance similarly as they do to isopentyl acetate, but it is not nearly as effective in producing a response, requiring 20 to 70 times as much compound before bees respond. Queen and drones lack 2-heptanone.
Scent or Nasonov Gland
Workers have a scent (Nasonov) gland at the tip of the abdomen. The gland emits a mixture of seven terpenoids which serve primarily in orientation. To release the chemical mixture the workers stand high on the hind legs with the abdomen elevated and tilt the last abdominal segment downward while fanning the wings. Bees use the scent to help sisters locate home, food, and water sources. It acts with queen substance in a pheromone concert to keep the bees of the swarm together.
Other Pheromones
Honey bees have a trail pheromone that includes chemicals released from their lowest leg segment, which serve as orientation pheromones. Brood, drones, and beeswax comb emit pheromones . the former helps to maintain queen dominance as it is responsible for retarding worker reproductive organ development. The mixture of pheromones plus the distinctive queen signature pheromone, mix with food odors to give each bee colony a distinctive hive odor. Hive odor is not a specific pheromone but does impart a chemical identity to each social unit.
Back to Basic Bee Biology for Beekeepers table of contents
Source:
The above text is taken from The Mid-Atlantic Apiculture Research & Extension Consortium, Basic Bee Biology for Beekeepers; Fact Sheet,MAAREC Publication 1.4 March 2004. You can download this factsheet and others at the MAAREC website