29 May Laying Workers & How To Fix It

Each season, inevitably, I find a colony that has become queenless.  To fix this nearly hopeless situation, you’ll need another healthy colony to pilfer resources from. This is one of the reasons why I recommend that you keep more than one bee hive.  Sometimes, when caught in the early stages, colony genetics can be preserved.  Preservation of genetics can only be done if the beekeeper catches the problem within 3 days of the queen’s death or departure; however, this makes the problem difficult to identify in the early stages.  If the colony goes queenless for more than 21 days, a majority of the foraging worker bees will have fully developed ovaries, which occurs in the absence of pheromones regulated by the presence of the queen, and they begin laying many eggs in multiples inside single cells.  This can be very difficult to correct once it happens.  Most beekeepers suggest combining colonies and counting your losses because the colony becomes faithful to the laying workers.  This makes queen reintroduction much more difficult because they see her as an unwelcome intruder and will likely kill her if not done properly. 

How Did This Happen?

The short answer is the colony failed to requeen.  At some point, the colony absconded, swarmed, or failed to supersede their queen.  An absconded hive likely leaves with most of the population, so little to no brood remain that are capable of being reared into a queen.  A swarmed colony or supersedure will typically have worker bees that can rear remaining larva and eggs to be the next queen.  In this case, a new queen must go on mating flight(s).  For a queen bee, mating flights are very dangerous because she is vulnerable to predation.  If a queen is preyed upon during this time, the colony is most certainly doomed.  After 21 days without the queen, the colony will develop laying workers in a last ditch effort to survive, which is a hard-wired evolutionary survival mechanism, despite the fact that these laying workers are sterile. 

Here, again, honey bee biology is fascinating, and their reproduction is very different from other animals that are not eusocial insects.  Honey bees form one of the most complex animal societies through a haplodiploid structure where a single reproductive queen is supported by her thousands of sterile worker caste daughters. These female workers are diploid and their brother males are haploid.  While the worker bees can activate their ovaries in the absence of the queen, the eggs they contain have not been fertilized, so their offspring will all be haploid male drones.  Drones are essentially all genetic clones of the queen in a queenright colony.  In a queenless colony, since drones are haploids, they have the genetics of the laying worker that produced them.  Without intervention a queenless colony will fail as its population becomes exclusively drones.

How To Recognize Laying Workers

In the early stages, laying workers can be difficult to detect from entrance observations because workers will also forage for pollen and nectar, even when they are also laying eggs.  The colony may be laying unfertilized eggs within the nest, but outside foraging appears normal.  This behavior can be observed because rearing drone brood requires nectar and pollen similar to the diet of worker brood.  Laying workers are capable of doing all worker bee tasks, including foraging, nest defense, wax production, brood feeding, and nest cleaning.  Due to this, laying workers are virtually impossible to distinguish.

A brood box inspection will reveal evidence of laying workers.  Inside the hive of laying workers, you will find cells filled with multiple eggs due to the many workers with developed ovaries all walking around laying eggs one on top of another throughout the hive.  When compared to a queenright colony, you will notice that a queen is the only laying bee, and she will usually lay one egg per cell.  There is an exception to this, when a new queen is beginning to lay eggs she may temporarily lay multiple eggs per cell as she learns her skill/job.  A queenless colony will have many workers laying and you will not see large numbers of individual eggs per cell.

Upon further hive inspections, a colony with laying workers will have brood frames that look uneven across the surface.  This uneven surface is called “raised brood”.  Raised brood happens because the laying workers are laying unfertilized eggs that will develop into drones.  These drone eggs are being deposited into cells that are designed for worker bees.  As the larger drone brood develops from larva into pupa, the nursing workers have to extend the wax cell to accommodate the larger drone brood.  After drones hatch, the brood frame is left with an uneven or “raised brood” appearance.

How To Fix This – 3 Steps

The first decision toward correcting a colony with laying workers is to assess whether the colony is worth saving.  The beekeeper must determine if the population of workers is strong enough to be saved.  If not, your only options are to allow the hive to fail or combine with a stronger colony.  If yes, and there are enough workers to sustain the colony, then you may have a chance to correct this hopeless state, saving the colony from certain doom.

Once you have determined that you have laying workers and the colony is worth saving, you now need to begin the 3-step process of correcting the problem.  The problem is that workers are acting as interim queens and the colony is faithful to them.  Any queen that is introduce at this point will be seen as enemy by the colony and promptly killed.  This kin recognition in honey bees is very strong, and it turns out to also be colony specific.  Recent findings show that honey bees can recognize nestmates by their gut microbiome through greeting exchanges of their proboscis, which might offer a mechanism that explains how the method of reintroducing a queen to a queenless colony can work.

STEP 1: Remove Drone Brood Frames

The first step toward correcting a colony with laying workers is to remove their drone brood frames.  The eggs that the laying workers contribute are destined to be drones, and drones are not capable of helping correct the colony.  At this stage of a queenless colony, raising drones becomes detrimental because they will be competing for any resources and care from the workers attending the new brood you will be introducing (next step).  Additionally, the eggs laid by the works are genetically theirs, and they may prioritize the care of the brood that they recognize as their own.  To avoid this, I recommend removing these drone brood frames and make room for replacement worker brood frames from another colony.

STEP 2: Introduce Worker Brood Frames

The second step toward correcting a colony with laying workers is to add frames of all 3 stages of worker brood from another colony.  Only add brood frames without adult workers.  Any accompanying worker bees will be killed upon introduction, since they will be recognized as an enemy not as kin (which again is linked to the lack of shared gut microbiome, that appears to be like a unique signature for each colony).  Once in the nest, the presence of worker brood pheromones will help restore order, while emerging workers will start rearing brood as the older “laying” workers die off.  In time, as the bees share food and socialize, the workers from the two colonies will begin to recognize each other as nestmates. 

Check to see if the colony has accepted brood frames 1-3 days after introduction.  Repeat worker brood frame introduction if the previous brood has been rejected and cleaned out.

STEP 3: Requeen With Time

The third step, once the colony with laying workers has accepted frames of brood from another hive, is introducing a new queen or queen cell.  You will want to introduce your new queen through a candy plug cage. A purchased queen will come with her own attendants. If using a queen cell or queen from your own hives, use a cage with 4-5 attendants to ensure her survival in the cage long enough to allow for this acclimation period.  This introduction phase must last at least 5-7 days.  Beekeepers who get too anxious and release the queen early will find that the colony may not accept the queen and kill her.  The key here is time.  After 5-7 days caged inside a queenless hive, the colony will detect the queen’s pheromones as they feed and socialize with her.  In honey bees, this social feeding has been shown to be an important way to identify nestmates.  Queen introduction methods suggest there is both a genetic role in kin recognition (more closely related bees are more likely to be recognized as family) and a gut microbiome role in nestmate recognition that factors into successful introductions.   This may be why queen introductions to a queenless hive must last at least 5-7 days and occur through shared food barrier, such as the candy-plugged cage.  While this has been attributed to time to allow pheromones from the queen to be perceived by the colony, the gut microbiome influence on neurological behavior, including queen introductions, provides intriguing possibilities to explore.  Perhaps future research will show that successful queen introduction relies upon synchronization of the gut microbiome of the new queen to that of the colony.

Works Cited

Page R E, Erickson E H. 1986. Kin recognition and virgin queen acceptance by worker honey bees (Apis mellifera L.). Animal Behaviour, 34; (4):1061-1069; ISSN 0003-3472, https://doi.org/10.1016/S0003-3472(86)80165-8.

Tilley C A, Oldroy B P. 1997. Unequal subfamily proportions among honey bee queen and worker brood, Animal Behaviour, 54; (6):1483-1490; ISSN 0003-3472, https://doi.org/10.1006/anbe.1997.0546.

van Zweden J S, D’Ettorre P. 2010. Nestmate recognition in social insects and the role of hydrocarbons, in Insect Hydrocarbons (Cambridge Univ. Press), pp. 222–243.

Vernier C L, Chin I M,  Adu-Oppong B,Krupp J J, Levine J,Dantas G, Ben-Shahar Y. 2020. The gut microbiome defines social group membership in honey bee colonies.Science Advances, 6; (42) eabd3431; DOI: 10.1126/sciadv.abd3431