Alarm Pheromone
Lexikon
When a bee stings, it releases an alarm pheromone at the base of its sting and from its mandibular glands, a chemically complex mixture of several dozen scent compounds.
When a bee stings, it releases an alarm pheromone at the base of its sting and from its mandibular glands, a chemically complex mixture of several dozen scent compounds. The main component is considered to be isopentyl acetate, also called isoamyl acetate, a substance with a smell reminiscent of bananas that beekeepers find characteristic. The scent clings to the site of the sting and, in effect, marks the attacker as a target for further stings.
Other guard bees nearby react to this signal with heightened readiness to defend, direct their attacks specifically at the marked spot, and become more aggressive overall. This means a single sting can quickly turn into a coordinated defensive attack by several bees, especially when many guards are standing near the hive entrance.
For everyday work at the colony, this means: after a sting, move away from the hive entrance as quickly as possible and do not treat the affected spot right in front of the hive, because the scent attracts further bees there. Smoke from the smoker effectively masks the alarm pheromone and calms the colony, which is why careful beekeepers would rather smoke a bit too much than too little with nervous colonies. A common mistake is simply leaving squashed or crushed bees lying around, since injured bees also release alarm pheromone and can needlessly agitate a colony.