A Honey Bee's Perspective: Smell

Thursday, 10 August 2023

Honey bees are eusocial insects, meaning that they live in large cooperative groups that have a division of labor throughout the colony. To be able to have this level of organization, honey bees need to communicate properly for raising brood, defending the colony, cleaning the hive, foraging, mating, and navigating. Honey bees communicate using many different senses, but smell is one of the most important. Their ability to detect pheromones of other bees and scent profiles in nature helps a honey bee to be successful in providing for their colony. 

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A Honey Bee’s Perspective: Smell

A honey bee’s antennae attach to the head in a bowl-like depression, called an antennal socket. There are four muscles attached to the base of the antennae which control the movement. There are three segments of the antennae, moving up from the socket, in order, are the scape, pedicel, and flagellum. The flagellum is made up of sub-segments called flagomeres, the female bees have 10, whereas the male bees have 11. The inside of the antennae has nerves that run from the sensory receptors to the antennal lobe of the bee’s brain (Burlew, 2018).

The antennae of honey bees have many sensory receptors, such as plate organs, peg organs and hairs. The plate organs are chemo- and photoreceptors responsible for olfactory and visual signals. The peg organs are chemoreceptors also responsible for olfactory signals. The plate organs are used as most of the honey bee’s olfactory sensors and are found on the last eight flagomeres of the antennae. The queen bee has roughly 3,000 plate organs, the workers can have up to 6,000, and the drones can have up to 30,000 (Sammataro, 2021).

Honey bee on wild blueberry flower (ATTTA©2021)

Honey bees are generalist pollinators and are not bound to a limited number of plants for gathering food. However, individually, bees are ‘flower constant’, and they memorize features of a given floral species. Memorized features include odor, color, shape, and texture, but odour plays the most prominent role, where it is the most associated with nectar and pollen reward (Menzel et al. 1993). Floral aromas are a mixture of many compounds (Pham-Delègue et al. 1989). To maximize their profit from foraging, honey bees need to differentiate between very subtle floral odor blends (Pham-Delègue et al. 1989). Also, honey bees can also detect the various chemicals that make up aggregation and alarm pheromone blends.

Honey bees can detect various functional groups, including primary and secondary alcohols, aldehydes, and ketones. However, what is interesting is that the size of the molecule is more important for honey bees recognizing various odours than the chemical group. Thus, chemical dimensions seem to be encoding into the brain of honey bees (Guerrieri et al. 2005).

Honey bees highly rely on olfaction for foraging purposes, where they use floral scents as guiding cues for long distance flights (Stopfer et al. 1997). However, floral bouquets can change in the air due to differences in volatility of the different compounds (Mauelshagen, 1993; Strausfeld, 2002). Therefore, honey bees rely on multiple senses to maximize their profit from foraging (Mauelshagen, 1993; Strausfeld, 2002). When a successful forager returns with nectar, she brings the food scent in the honey crop or clinging on her body. These odour cues act as an attractant or orientation guide for other members of the colony. Interestingly, information on a food source will reach more members of the colony as the food profitability (sugar concentration) of the collected nectar increases (Grüter et al. 2006) These olfactory cues are likely to have a positive effect on the foraging performance of honey bees.

Olfaction is one of the most important senses honey bees have when it comes to communication. The use of smell is crucial for honey bees to effectively defend the colony and forage for food. If you are interested in learning more about the honey bee communication, and their senses, be sure to continue reading our blog.

Connecting with ATTTA Specialists

If you’d like to connect with ATTTA specialists or learn more about our program, you can:

visit our website at https://www.perennia.ca/portfolio-items/honey-bees/

Email abyers@perennia.ca

Burlew R. 2018. A quick-start guide to honey bee antennae. American Bee Journal 158(2):157-160.
Guerrieri, F., Schubert, M., Sandoz, J.C., Giurfa, M. 2005. Perceptual and neural olfactory similarity
in honeybees. PLoS Biol 3: e60.
Grüter, C., Acosta, L.E., Farina, W.M. 2006. Propagation of olfactory information within the
honeybee hive. Behav Ecol Sociobiol 60 (5): 707 –715.
Mauelshagen, J. 1993. Neural correlates of olfactory learning paradigms in an identified neuron in the honeybee brain. J Neurophysiol 69: 609 – 625.
Menzel, R., Greggers, U., Hammer, M. 1993. Functional organization of appetitive learning and memory in a generalist pollinator, the honey bee. In: Lewis AC (ed) Insect learning. Chapman & Hall, New York/London. pp 79 – 125
Pham-Delègue, M.H., Etiévant, P., Guichard, E., Masson, C. 1989. Sunflower volatiles involved in honeybee discrimination among genotypes and flowering stages. J Chem Ecol 15: 329 – 343.
Sammataro S. 2021. A beekeeper’s handbook: fifth edition. Cornell University Press. pp 16.
Stopfer, M., Bhagavan, S., Smith, B.H., Laurent, G. 1997. Impaired odour discrimination on desynchronization of odour-encoding neural assemblies. Nature 390: 70 – 74.
Strausfeld, N.J. 2002 Organization of the honey bee mushroom body: representation of the calyx within the vertical and gamma lobes. J Comp Neurol 450: 4 – 33.