How Do Bees Communicate with Each Other?

How Do Bees Communicate with Each Other?

How do bees communicate with each other? Learn about different honey bee pheromones, the chemical substances secreted by exocrine glands, and the hive tasks they achieve.

When Karl Von Krisch broke the news to the scientific and beekeeping world about bee dances in the late 1920s, it was described as “the most astounding example of non-primate communication that we know,” and landed him an overdue Nobel Prize.

But, of course, von Frisch’s work barely scratches the complexity and sophistication of honeybee communication. We now know that the invisible communication of pheromones drives a vast amount of behavior.

In the animal world, pheromones are chemical substances secreted by exocrine glands. The purpose of these chemicals is to drive a behavioral or physiological response by others of the same species. Pheromones are widespread in the animal kingdom and can be categorized into two types: primer pheromones and releaser pheromones. Primer pheromones trigger complex and long-term changes in the receiver at the physiological (bodily) level, such as growth or development. Releaser pheromones are the weaker of the two types and trigger a simple and short-term response in behavior in the recipient.

Social insects — including ants, wasps, hornets, and bees — have enormously complex colonies with multiple castes assigned specific roles. What seems like chaos to an outside observer is highly regulated at the chemical level. It’s impossible to underscore the role pheromones play in the behavior and life cycle of all social insects.

In honeybees, pheromones guide reproduction (for the queen), swarming, foraging, defense, orientation, and communication among castes (queen to workers, workers to each other, queen to drones, adult bees to brood, etc.). The sophistication of these scents permits a hive’s coordination and complex activities while allowing it to respond to unexpected occurrences or changing environmental conditions. The quantity and types of honeybee pheromones are almost too numerous to list. Highlights include:

Queen Pheromones

The queen bee is responsible for a colony’s main regulations and functions, mostly achieved through a complex blend of pheromones known collectively as the “queen signal.”

The queen can regulate her workers in several critical ways, both behaviorally and physiologically (bodily). Through chemical controls, she can establish the social hierarchy, maintain worker cohesion, allow kin to recognize each other, and stimulate cleaning, building, guarding, foraging, and brood feeding. Queen pheromones also call workers around her to groom and feed her.

Pheromones are what attract drones during mating flights. Mating appears to be a crucial factor in developing the queen’s chemical signal and its attractive effect on workers.

During swarming, the queen’s pheromones keep the swarm clustered together. The swarm will return to its original hive if the queen dies or cannot fly.

Pheromones also allow the queen to maintain her reproductive supremacy by inhibiting worker reproduction and suppressing queen-rearing by the workers. When the queen’s pheromones begin to decline (due to age or illness), the queen’s iron grip on the colony lessens, and the reduction in pheromones signals the workers to rear new queens.

Worker bees possess ovaries, but the queen inhibits the development of oocytes (immature egg cells). However, worker bees’ ovaries can become active and lay eggs in her absence. Because these eggs are infertile, they only produce male offspring. However, some workers will lay eggs even with the presence of a queen. In this case, egg-discriminatory pheromones direct policing behavior in which workers kill off these unregulated eggs while leaving queen-laid eggs alone.

honey-bee-Queen-pheromone-communication
by Adobestock/Ivan

Queen pheromones also regulate colony defense. The defense consists of recognizing predators, alerting nestmates, adopting threatening postures, buzzing, and, of course, stinging. Counterintuitively, colonies without a queen are more aggressive than those with a healthy queen.

Worker Pheromones

While the queen dominates the chemical realm in which bees live, workers don’t have specific methods of pheromone communication. Worker bees perform different tasks depending on their age. This is termed “temporal polyethism,” and it’s determined by the workers’ glandular plasticity (the ability of glands to alter and change with age and adapt to the colony’s changing needs). Such tasks as wax production (usually found in young bees) or colony defense (usually performed by older bees) are not rigid and can change in accordance with need.

Workers can regulate their own task allocation. When there are many foragers, their pheromones inhibit the development of younger bees, which then devote themselves to nest occupations. When the number of foraging bees declines, the inhibitions of the younger bees drop, and they develop into new foragers.

Worker pheromones also contribute to the marking of the hive entrance, swarm clustering, and marking of foraging sources. Chemical signals also trigger “hygienic behavior” (detecting and removing sick larvae) and removing dead bees within the colony.

Using Smokers

Smoke decreases the alarm pheromones in workers, which is why beekeepers use smokers to calm a hive. Smoke decreases the sensitivity of workers to the smell of their alarm pheromones.

Because bees are so sensitive to pheromones, interrupting this chemical communication isn’t hard to do. The results can be catastrophic or beneficial. While, sadly, catastrophic interruptions of honeybee communications are common (smoke from wildfires, for example), once in a while, beneficial interruptions are possible.

For example, research is ongoing about using a synthetic pheromone to trigger increased “hygienic behavior” in workers. This behavior monitors the brood’s health and is being investigated as a method of controlling varroa mites.

The eastern honeybee, Apis cerana, originally hosted varroa mites. This species developed resistance mechanisms to varroa mites because of their increased hygienic behavior (detecting, uncapping, and removing diseased or parasite-infested brood from the colony). In short, hygienic bees smell disease and do something about it.

Because hygienic behavior is a genetic trait — meaning it is heritable — efforts are being made to create disease-resistant honeybees that exhibit higher hygienic behavior by testing for the trait and using queens with the highest propensity for the trait. While some hygienic bee lineages are emerging, all bee breeders can (and should) select hygienic behavior to fight varroa mites.

Having even a superficial understanding of the role of pheromones in honeybees merely contributes to the enduring fascination we continue to hold toward these creatures. Perhaps, in a way, bees are using pheromones to control us, too.


Patrice Lewis is a wife, mother, homesteader, homeschooler, author, blogger, columnist, and speaker. An advocate of simple living and self-sufficiency, she has practiced and written about self-reliance and preparedness for almost 30 years. She is experienced in homestead animal husbandry and smallscale dairy production, food preservation and canning, country relocation, home-based businesses, homeschooling, personal money management, and food self-sufficiency. Follow her website http://www. patricelewis.com/ or blog http:// www.rural-revolution.com/.


Originally published in the January/February 2024 issue of Countryside and Small Stock Journal and regularly vetted for accuracy.

Sources

https://www.ncbi.nlm.nih.gov/ books/NBK200983
https://www.nature.com/articles/ s41598-020-64144-8
https://royalsocietypublishing. org/doi/10.1098/ rspb.2019.0517#d1e1441
https://www.sciencedirect. com/science/article/abs/pii/ B9780128196281000067
https://www.ncbi.nlm.nih.gov/ books/NBK200983
https://www.sciencedirect. com/science/article/abs/pii/ S0022191021000482
Thomas D. Seeley. The Lives of Bees. Princeton University Press. 2019.
https://backyardbeekeeping. iamcountryside.com/health-pests/ hygienic-bees-smell-disease

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