Diet, genetics and hive environment are what most beekeepers think of when assessing queen health, and fair enough, these are 80% of it. The other 20% is in factors like mating success, internal hive environment and hormonal profile (amongst others). In the larval stage, nutrition heavily influences the adult queen’s characteristics- think size, weight, ovariole development. In the adult stage, the factors become similar to a worker bee- good nutrition, good hive environment, low stressors.
This article will examine what makes a queen bee healthy from intrinsic (“internal”) & extrinsic (“external”) factors. The advice for beekeepers will be the same: Keep strong hives and place them in areas of diverse forage. Sugar syrups and pollen patties are supplemental feeds and will not replace a diet of diverse plant pollen and nectars.
There’s a shirt that goes with this article – designed & pressed by Yours Truly.
Nutrition
Queens are fed royal jelly: a protein-rich secretion from the nurse bee’s hypopharyngeal gland1, as the mature worker bee’s carbohydrate-only diet is insufficient (see Haydak, 1935, a time when people thought pollen-free diets were viable!). The queen’s fat body stores are insufficient to maintain a constant laying rate of >2000 eggs a day, so ingesting the jelly promotes physiological changes that lead to increased production of egg yolk proteins, eventually readying an egg for laying.
The queen is fed frequently, every 10-15 minutes… I have not observed this during my inspections (too busy avoiding stings) and I’m told it’s a similar process to trophallaxis, whereby worker bees feed one another mouth-to-mouth. Unsurprisingly, the quality of pollen affects the quality of the royal jelly; bees fed from nutritionally diverse pollens produced more nutritious jelly (as measured by 10-HDA concentrations; Pattamayutanon et al., 2018).
Trophallaxis feeding means the food is already pre-digested by the worker bee, and this is reflected in Her Majesty’s gut microbiota. Queens had a higher number of Parasaccharibacter apium compared to workers and drones (Corby-Harris et al., 2014, Corby-Harris et al., 2016). This group of bacteria produces metabolic and development enzyme that aid in development of the egg membrane and is not present in workers.
These nutrients move from the gut into the bee’s blood (haemolymph) and are converted into energy. To put it technically, the fat body cells and oenocytes (secretory cells used in lipid processing and metabolism) detoxify fat-soluble compounds, whilst the nephrocytes (think kidney cells) absorb the circulating proteins and further remove toxins from the haemolymph. The remaining undigested material is passed into the hindgut for further absorption before the wastes are excreted as yellow bee poop.
Diet Quantity, Not Quality, Influences Caste Determination
What makes a queen? It can’t be due to the extra room given to her in a queen cell cup, as the rearing of emergency queens from worker-destined larvae proves otherwise. Slater and colleagues found that it is the quantity of the diet that determines the honey bee caste (Slater et al., 2020). We know that nurse bees continue feeding queen larvae with royal jelly, whereas the worker brood are switched to “worker” jelly after being a few days old (a relatively less nutritional compound; Wang et al., 2015).
Slater and colleagues found no significant impact on the adult bee’s caste when larvae were fed with a varied diet (varied levels of water, protein and carbohydrate levels in the jelly). This counters the general beekeeping wisdom of “queens and workers are genetically identical, it’s just that queens are fed royal jelly whereas workers are fed worker jelly. Queens are also reared in larger cells”. When larvae was fed in large amounts, more queens were produced, with higher carbohydrate concentrations producing more queen-like characteristics (Kaftanoglu et al., 2011).
Royalactin (MRJP-1) and Major Royal Jelly Protein-3 (MRJP-3) are the main royal jelly components influencing queen development, and when added in controlled quantities, did not lead to more queen bee development (Slater et al., 2020). MRJP-1 is involved in caste regulation (i.e. determining queenliness), and its effects are more prominent when fed in large amounts. The authors suggest there is more to it, however due to the difficulty in rearing queens in-vitro (i.e. in a petri dish), it is difficult to isolate the specific functions of each protein.
This is not saying quality does not matter, as anyone can tell you that an organism’s growth, development, and survival are impaired on low protein diets. It’s just that in honey bees, the concentrations of these macronutrients did not influence the final adult caste2. Nutrient diversity matters, and it must be above a certain threshold in order to maintain normal growth.
Hormones: Vitellogenin & Juvenile Hormones are Modulated in Queens
An earlier study by Corona & colleagues found that vitellogenin (Vg), the “egg yolk protein” is responsible for the long life and health of queen bees (Corona et al., 2007). Vg is involved in antioxidant defence, and its higher levels in queens suggest that it contributes to the queen’s longer lifespan. After all, being long-lived means Her Majesty better withstands environmental stressors. Vg levels increase with age, presumably to counteract the increasing metabolic wear-and-tear that comes with aging (Seehuus et al., 2006). This preserves the overall queen health from reactive oxygen species, mitochondrial, & cell damage.
In workers, Vg interacts with Juvenile Hormone (JH) in a negative feedback loop:
- Nurses have high Vg, low JH, to maintain their role as nurses (and delay development of forager-grade flight muscles, metabolism etc..). This preserves division of labour and ensures that nurses are prepared for brood rearing and jelly production.
- In times of forager shortage, the metaphorical switch flips, elevating JH levels and reducing VG to promote the early transition of nurses to foragers
- Foragers have low Vg, high JH. This promotes foraging behaviour- sensory responsiveness, flight muscle development, forager-related task proficiency, and so on.
In queens, Vg is high while JH is low, providing a long-lived effect that supports ovarian development (the gamete) and egg production (the components that surround it; Corona et al., 2007). Another proposed mechanism for the longevity of queens is via DNA methylation (Cardoso-Junior et al., 2018), which was found to be independent of the Vg-JH pathway. In this study, removing DNA methylation led to workers living longer with higher levels of Vg, without reducing JH levels. The authors suggest that “upstream regulation using the FOXO pathway” produced increased Vg expression, as similar results were seen in the German cockroach (Blattella germanica) & the Egyptian mosquito (Aedis aegypti).
In Other Arthropods, Vitellogenin Shortens Lifespan
Side note: studies in Drosophila flies and C. elegans nematodes showed that increased yolk protein expression leads to shortened lifespans as it downregulates the insulin-like growth factor signalling pathway (e.g. Dillin et al., 2002 or Tu & Tartar 2003). The opposite is the case in honey bees, whereby increased yolk protein (Vg) increased oxidative stress tolerance (Seehuus et al., 2006).
Seehuus and colleagues propose that this could be due to its chemical similarities with the antioxidant enzyme zinc dismutase, and could have emerged as result of the “the developmental trajectories of honey bee queens and workers being decoupled during the larval stage by an endocrine switch… enabling independent selection on the reproductive and alloparental phenotypes. This causes amplification of traits associated with oviposition to be amplified in queens while being reciprocally deleted in workers” (paraphrasing Seehuus et al., 2006). A mouthful, right? In simpler terms, the reverse of Vg activity in A. mellifera could be the result of mutations during the transition from worker to queen-destined larva.
Gut Microbes
When queen bee gut microbiota was transplanted into a sterile worker bee gut, the worker was found to live longer (Wang et al., 2024). The authors attribute this to a downregulation in the Insulin/Insulin-like Signalling pathway (IIS), which is known to improve the lifespan of invertebrates (think Drosphilla and C. elegans from above). Queen guts have a higher concentration of Acetobacteraceae and Lactobacillus bacterial groups, as well as the P. apium mentioned above. The Acetobacteraceae (Alpha 2.2) group along Bombella bacteria were proposed as the drivers behind this lifespan increase, as the former bacteria thrives in bees which are fed high levels of royal jelly- larvae and queens (Corby-Harris et al., 2014).
The mechanism behind IIS inhibition is thought to be due to increases in the activity of antioxidant genes via the FOXO signalling pathway. This generally leads to reduced reactive oxygen species (“ROS”) damage, delayed aging and extended lifespans.
Not much more could be said for gut microbiota that matters at the beekeeper’s level. Perhaps as research continues, we’ll start adding probiotics to our winter feeds to promote optimal colony health.
Physical Characteristics: a Large Queen is a Good Queen
Ask a beekeeper what makes a good queen and they’ll say “genetics. Choose one that comes from a strong hive, with strong parents” (now ask them what makes a good human…). *ahem*- Facchini and colleagues investigated these traits, finding factors like “body weight, spermatheca volume, number of ovarioles, and number of stored sperm to be promising breeding goals” as they are strongly influenced by genetics (Facchini et al., 2011). In practice, this means a larger queen can hold more eggs, more sperm and have more ovarioles- all desirable characteristics to make a strong hive.
Characteristics that are largely determined by genetics (i.e. the parents) are structural: the head and thorax size and weight, wing length and leg width. The wings and legs are attached to the thorax, and these muscle-chitin attachments are closely regulation from a developmental standpoint. Abdomen weight was more phenotypically determined (i.e. from the environment- feeding, temperature and so on). Abdomen size was correlated with total bodyweight, which I interpret as where most of the queen’s “value” is held: egg laying, sperm storage and food digestion. Larger abdomens, larger bodyweights, larger sperm storage, larger egg laying. Theoretically of course.
Internal Hive Environment
Temperature
Extracted from temperature limits of honey bees
In a winter cluster, the queen is kept warm at the core with her normal retinue of worker bees. In hot conditions, she her retinue follows her into the cooler parts of the hive. Her Majesty rarely experiences temperature stress under normal conditions. Where queens experience temperature stresses is outside the hive (e.g. during shipping or in weak colonies during extreme heat events– think heatwaves).
A healthy mated queen can survive brief exposure high temperatures (up to ~42°C recorded by McAfee et al., 2021), but the beekeeper’s real concern is not in immediate survival rather her reproductive health. After mating, the queen stores sperm in her spermatheca, and these gametes are sensitive to temperature, remaining near 100% viable between 15 °C and 38 °C (McAfee et al., 2020). Exposure beyond this range, even for a short while, greatly reduced the number of live sperm.
If you’re thinking that this leads to partially or wholly-infertile queen, you are correct, and it is (very likely) she will be superseded by the colony. If you were thinking this would be obvious due to an abnormal laying pattern… you are also correct, provided that queen continues “laying blanks” for several months. Why? Because McAfee and colleagues found that both temperature extremes did not impact laying pattern in the short term (2 weeks post exposure; McAfee et al., 2021)- probably because queens release multiple sperms to fertilize a single egg, and at this point, the sperm stores have not been substantially reduced to mark her for supersedure.
Briefly: Humidity
We don’t hear much on humidity for queen health, and for good reason- water management is rarely an issue for most beekeepers, unless you happen to be in a desert… even then, your local A. mellifera subspecies would be adapted to low water levels (see an example from A.m. jementica). Humidity matters for egg laying, with eggs requiring a high absolute humidity to hatch normally. Higher humidity also has the bonus of increasing the time required for small hive beetle eggs to hatch. All up, humidity does not impact the individual bee’s health, rather that of the brood.
Light
Shipgler and colleagues showed that queens functioned well in total darkness, laying eggs non-stop without a “day-night” distinction (Shipgler et al., 2022). They tested three variables: constant darkness, constant light, and twelve hours light followed by twelve dark. They found that:
- Queens under constant light performed poorly. I am unsurprised, for hives are dark places and honey bees evolved to function under this minimal light– they communicate via touch, smells and sounds, not vision.
- Queens in the 12:12 light:dark group performed just as well as those in constant darkness.
This study attempted to answer the questions surrounding how queens lay ~2000 eggs a day. Does she lay an egg every two minutes around the clock with no rest, or in batches followed by rest? Their results showed that honey bee queens are active around the clock with little-to-no inactivity (Shipgler et al., 2022).
In her early days post-mating, she shows a circadian rhythm, i.e. recognising a “day” and “night” time, with reduced activity at night. This is an aftereffect of her virgin days (“gyne”), where she behaved like her sister worker bees- flying in and out during the day and resting inside the hive at night. When the post-mating changes are complete, her reproductive state drives her to continue laying.
Regarding the observation of queens laying under a 12:12 light:dark regime, the authors note that this is an anomaly, suggesting “Perhaps the stress associated with constant light, but not with a 12:12 LD regime, was high enough to compromise oogenesis [egg development] or block the laying of mature eggs” (Shipgler et al., 2022). Beekeepers have seen how queens react to light, fleeing into the darkest part of the frames, so it is understandable that this stress causes them to cease egg laying.
Pesticides, Pathogens and Other Stressors
The list of stressors and impact on Queen health go and on, so I conclude with bullet point summaries:
- Pesticides can impact the queen directly or indirectly:
- Directly poisoning her, leading to replacement via supersedure, or killing her outright, leading to emergency queen rearing (looking at you, formic acid Varroa treatments).
- Indirectly, by sublethal effects on the worker bees leading to a reduced hive inefficiency and insufficient care for the queen or her brood.
- Older queens have reduced egg laying capabilities, whether due to lowered sperm stores or ova count. Their pheromone concentrations may decrease, weakening her control over larger colonies.
- All these factors make her more susceptible to supersedure, assuming you don’t replace her first.
- Pathogens like:
- Nosema spp. Can infect the queen’s gut and ovaries, impairing egg-laying.
- Varroa mites indirectly affect queens via virus transmission and colony stress.
- Braula flies are pests that reduce the amount of food a queen consumes.
- Viruses are plentiful, from DWV to ABPV and other acronyms ending in “V” – all have various effects on the hive, albeit indirectly on the queen.
- Transportation and queen handling during shipping can cause mechanical stress, or expose her to temperature extremes, resulting in reduced sperm viability, survival and performance and pheromone production.
- For those who purchase queens, queen rearing practices matter:
- 12–24-hour larvae yield better queens than older larvae when grafted onto the queen cups.If the queen is reared in an area of low drone diversity or poor nutrition leads, she can end up underperforming.
- Artificial insemination vs natural mating affects sperm longevity and genetic diversity – the skill of your inseminator (ha ha) matters greatly here. Natural mating is also a gamble, sometimes Her Majesty is not open for business.
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Footnotes
- The review of Fevre & Dearden (2024) states that we don’t exactly know what queen bees are fed, only that it is commonly accepted to be a form of jelly similar to royal jelly. They base this uncertainty on how different types of jelly composition are given to different castes in their larval stage.
Why is it difficult to assess, you ask? I would wager it’s because the queen never-self feeds, her food is fed to her by the retinue, and you can’t observe what she consumes directly; the contents may be pre-processed or blended, making it hard to trace the individual nutrients back to their origin. If you try to sample a queen… good luck, she’ll be dead and you may end up killing the colony if they fail to replace her. This sampling would have to be done in a narrow timeframe as her fast metabolism means the gut is usually empty. ↩︎ - I deliberately omit drones when writing on “adult castes” as they come unfertilized eggs. The above studies on diet quality and quantity will not impact the drone outcome because drones all come from unfertilized eggs. You can feed the drone worker or royal jelly, it won’t become a queen or worker- it’ll still end up a drone- genetics comes first. ↩︎