swarm

To Catch A Swarm 2 – What Is A Swarm?

I have become quite interested in honey bees (Apis mellifera).  My interest has turned into an absolute obsession as I crave any new information that I can find regarding the topic of bees.  However, in my search for credible knowledge, I have found plenty of misconceptions and misinformation about the most studied insect on the planet.  Honey bees and humans have coexisted for thousands of years. 

An 8,000-year-old rock painting discovered at Arana Cave near Valencia, Spain, depicts a person climbing a ladder to gather honey from a hive on a cliff face.

Yet today, faced with the sixth mass extinction in the planet’s history, insects are disappearing faster than science can record their existence.  Insects play a critical role in ecosystem function.  Without insects, humans will not thrive, as nearly 1/3 of our food supply is derived from insect pollination.  Now is the time to learn about insects and respect their place on the planet.  Honey bees are a gateway to understanding the insect world. 

Through this blog, I will help you understand more about honey bees, and will provide you science-based information to assist you in catching a wild swarm. The information I will be providing represents what I have learned while researching the scientific literature about honey bee swarms, as well as my first-hand application of these methods to confirm the results.  This information can be used to lure wild honey bees to take up residence.  Once captured, the honey bees may be managed for honey production, agriculture pollination, or just kept for personal enjoyment and ecosystem benefits.  Whatever your intentions, I encourage everyone to learn more about honey bees and ultimately, to become a beekeeper. 

What Is A Swarm?

Honey bees can reproduce as a colony, also known as swarming.  The process of swarming causes the original colony to create new queen(s).  When the new queens are about to hatch, the original colony splits into two or more colonies as queens exit the hive.  Groups of bees escorting the queen will ultimately form the “swarm” around the queen.  Honey bees are most likely to swarm during spring and early summer.   However, bees are capable of swarming anytime of year if the proper conditions are met.

How Do Bees Swarm?

Before a swarm can take place there are some steps the hive must go through to prepare for the move.  First, they must create a new queen.  This is done by drawing out several selected egg cells into queen cells and feeding the larvae exclusively royal jelly (no pollen).  Right before the new queens emerge, the old queen will stop laying eggs in preparation for flight.  The workers will tug and chase the queen around the hive to prevent her from laying eggs.  Please note that a queen can ALWAYS fly, but in preparation she shrinks a bit to allow for the extended flight needed for swarming.

Once she’s ready and new queens are about to emerge, the old queen leaves the hive taking with her 1/3 to 1/2 of the colony population.  Typically, the swarm contains most of the experienced foragers who already know their surrounding environment.  They will assemble on a nearby tree, bush, fence, or other structure while they search for a new home.  At this point, there are now two colonies.  So, swarming is considered a reproduction strategy at the colony level. 

The very first thing that the swarm does is assemble into a ball-like formation on a tree or other suitable structure.  In beekeeping, this ball of bees is called a bivouac. 

bivouac | ˈbivo͞oˌak | noun “a temporary camp without tents or cover, used especially by soldiers or mountaineers.”  Origins, early 18th century (denoting a night watch by the whole army): from French, probably from Swiss German Bîwacht ‘additional guard at night’, apparently denoting a citizens’ patrol supporting the ordinary town watch (Apple Dictionary).

The bivouac is where the bees will unite until the scouts can locate another place to live.  Once bees are in the swarm phase, they must undertake the task of finding a new nest location.  The choice of nest location by honey bee swarms is not fully understood. 

Nest Preferences

Research suggests that bees have several criterion that make perspective nest locations desirable.  There are at least six nest site variables that bees use to assess overall quality, including cavity volume, entrance direction, entrance size, entrance height from ground, entrance height from cavity floor, and presence of combs from an earlier colony (Seeley 2010).  Based on prior research, we know honey bees show specific preferences for several of these variables.  For example, swarms show preference for artificial cavities (nest-box) that are 10-12 feet off the ground, a bottom entrance nest-box that faces south, an entrance no larger than 2 square inches, and a nest-box volume of 11.1 gallons (Seeley and Morse 1978). 

Scout bees undertake the task of shopping for a new nest location.  Scouts are most likely older worker bees who are experienced foragers and know their way around the landscape.  As the bivouac waits on a nearby tree branch, the scouts are sent out to locate a suitable new home.  Once scouts return, they dance to communicate the location of the potential new nest, just like when foragers advertise food resource locations.  The scouts will study the dances of each other and go to those locations to inspect for themselves.  If the new location is better than the one they found, then these scouts will dance for the new location instead.  If this new location is not as adequate, the scouts will continue to dance for their original location.  Using this method, eventually all the scouts will reach a unanimous decision and all will dance for the same location (Seeley 2010).  Once this happens, the bivouac will dislodge from their ball and fly to their new home.

Pheromones & Nasanov

While we are not certain how honey bees communicate information about the potential new nest sites to the swarm, we do know that pheromones play a role in this communication process. The Nasanov gland, which emits a lemon-scented chemical cocktail, is located on the dorsal surface of the worker bee’s abdomen and is named for the Russian scientist who first described it in 1883.  It is currently unknown which bees discharge these pheromones, but one hypothesis suggests it is done by scout bees, while another considers it is conducted by workers known as ‘streaker’ bees – regardless, the end result is the swarm is guided toward the direction of the new nest location.

Once at their new home the swarm must immediately begin to draw up wax so the queen can lay eggs.  The foragers must get to work discovering and collecting all the resources the hive will need to get reestablished and prepare for overwinter survival.  Fortunately for them, they are all experienced foragers and their mother is already mated. 

Knowing that pheromones help honey bee swarms chose nest location, a beekeeper has the opportunity to influence nest choice.  Beekeepers commonly use lemongrass essential oil to lure local swarms to take up residence in a box and location of the beekeepers choosing.  Lemongrass essential oil contains geraniol, one of the chemical components of the pheromones found in the Nasanov gland.  However, pheromones produced in the Nasanov gland have a more comprehensive chemical signature than lemongrass oil (Schmidt, Slessor and Winston 1993).  It has long been known that synthetic Nasanov blends consisting of 1:1:0.5 citral:geraniol:nerol are superior swarm attractants (Free 1987).   In recent years, products such as Swarm Commander ® have entered the beekeeping market and offer assistance to hobby beekeepers in attracting feral honey bee swarms.  Swarm Commander ® is a proprietary blend of oils that mimics the natural pheromones emitted from the Nasonov gland.  According to Swarm Commander ®, they used Gas Chromatography and Mass Spectrometry to analyze the chemical signature of pheromones found in the Nasanov gland, and formulated their product to mimic the high-tech findings. 

Using all of this knowledge combined, a beekeeper can recruit wild bees at a location that the keeper chooses.  By following the procedures and processes that this blog publishes, you will be able to maximize your chance of successful swarm capture.  In the next blog, I will outline, in detail, how to build a swarm trap.  Stay tuned…

Literature Cited & Suggested Readings

  • Free, J. B. (1987). Pheromones of social bees. Ithaca, N.Y: Comstock Pub. Associates.
  • Schmidt, J. O., Slessor, K. N., and Winston, M. L. (1993). Roles of Nasonov and queen pheromones in attraction of honey bee swarms. American Bee Journal 133;58-60
  • Schmidt, J. O. (1994). Attraction of reproductive honey bee swarms to artificial nests by Nasonov pheromone. Journal of Chemical Ecology 20:1053-1056
  • Seeley, T. D., and Morse, R. A. (1978) Nest site selection by the honey bee. Insects Sociaux 25: 323-327
  • Seeley, T. D. (2010). Honey bee democracy.  Princeton, N.J: Princeton University Press.
  • Seeley, T. D. (2019). The lives of bees: The untold story of the honey bee in the wild.
  • Seeley, T. D. (2019). Following the wild bees: The craft and science of bee hunting. Princeton, New Jersey: Princeton University Press.
1 Comment
  • Connie
    Posted at 20:51h, 30 December Reply

    Interesting. Thank you.

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