The following is an excerpt from Eric and Joy McEwen‘s new book Raising Resilient Bees (Chelsea Green Publishing July 2023) and is printed with permission from the publisher.
In our early beekeeping days, we joined the Southern Oregon Beekeepers Association. Among the otherwise older membership was one younger, enthusiastic, and forward-thinking individual: John Jacob of Old Sol Apiaries, located in nearby Rogue River, Oregon. John is a pioneer in rearing queens from survivor stock—from honey bees that forgo treatment for control of varroa populations and live to tell about it. Like our early efforts, John’s projects experienced much criticism, and his queens were initially dubiously received. At the time, breeding queens of any sort was not a feat being undertaken in Oregon to any significant extent due to the much colder and wetter springs than the neighboring states to the south. Furthermore, queens raised from lines that were not the product of extensive line breeding with bees of known parentage were viewed as inferior. But John was a meticulous perfectionist. He taught us and others about the magic behind a well-reared queen and the methods required to reliably produce one, and Old Sol became the main source of new genetics into our isolated operation for many years.
One of the wisest things we ever learned from John was the foundation of the entire natural queen-rearing endeavor: understanding why bees raise queens in the first place. What is the impulse that bees are responding to when they raise a queen? What triggers their efforts? Can these conditions be replicated? And if so, can they be replicated in a manner that consistently stimulates the rearing of healthy, vigorous queens? The queens we had purchased over the years made it clear that the conditions of queen raising could be carried out poorly; John proved to us that there was a better way.
One reason a colony will initiate queen rearing is abundance. When a nectar flow is on and the hive is filling with nectar at a very fast rate, a colony may be overflowing with both young bees and the stores needed to support them. These positive conditions incite the bees to raise new queens in anticipation of swarming. One measurable factor that contributes to the swarm impulse is hive congestion. As the foragers require an ever-increasing amount of time to find house bees to whom they can transfer their loads of nectar, it becomes a cue to the colony that it is appropriate to initiate swarming. As you might expect, an abundance of both forage and young hatching bees are the conditions required to produce a superior queen.
The other reason a hive will raise a new queen is the absence of queen pheromone. When a queen’s pheromone levels are failing and the bees detect that her productivity is coming to an end, they will initiate the production of new queens. Likewise, bees will note an increase in the incidence of a queen laying unfertilized eggs in worker cells, a sign of depleted sperm stores in her spermatheca. Oftentimes a supersedure cell produced in a large colony that is aware of a failing queen can be of high quality as well, but the quality of the queen produced under these circumstances is very dependent upon the hive’s morale, health and the surrounding environmental conditions, such as nectar flow and availability of pollen. Learning to mimic both triggering conditions simultaneously in your queen-rearing process is the key to producing superior quality queens.
The process by which bees rear a new queen begins when the bees initiate queen cell production: the building or modifying of a cell to accommodate a queen larva of significantly greater size. The colony will typically rear multiple queen cells at once, to increase the chance of success. In the case of an aging or absent queen, this process is regulated by the reduction or absence of queen pheromones in the hive. In the case of emergency queen rearing, within a day of a complete absence of queen pheromones the bees will have begun to select suitable candidate eggs and larvae, tearing down worker-sized cell walls in preparation for constructing queen cells.
When bees rear multiple queens, workers have some influence on the sequence and timing of the queens’ emergence. Workers may select larvae up to 3 days old, as well as the most recently lain eggs, allowing for as much as a 5-day difference in age between queens. Worker bees can also manipulate the emergence rates of virgin queens by adding or removing wax from the operculum cap of the queen cell at the end of pupation. When this occurs, in concert with variation in when the eggs were laid by the queen, it can result in the emergence period extending over almost a week. This process typically results in the presence of multiple virgins in the colony at once, at which point the hive becomes an arena of activity. Virgin queens exhibit behaviors such as quacking, tooting and moving throughout the hive, all of which elicit a response from the workers. The queen who receives the most attention from the workers usually prevails as the sole reproductive female.
We sometimes see additional new queens emerge into colonies whose first virgin queens have already undertaken mating flights. This natural variation in timing adds resilience to the queen-rearing process by ensuring the presence of “back-up queens” in the event that an earlier virgin is lost while mating (a not-uncommon occurrence).
When a queen is reared artificially via the grafting process, a capped queen cell is placed into a queenless mini-colony arranged in a new box for this purpose (typically referred to as a “mating nucleus colony”). The presence of a mature queen cell and the pheromones emanating from it inhibits the colony’s instinct to rear additional queens. This leaves the colony with only a single chance to successfully nurture to maturity a new reproductive queen, making the colony vulnerable to environmental events and dependent on the quality of that human-reared virgin queen. It is true that if the colony rejects the cell immediately while there are still eggs and young larvae present, the nucleus colony can undertake the process of rearing a new queen. But unless the nucleus colony was intentionally prepared with this in mind and contains ample eggs and young larvae from which to select, a sub-optimal outcome is likely.