Honey bee life cycle: egg, larva, pupa, development times for queen, worker and drone, and how long bees live

The honey bee life cycle has four stages: egg, larva, pupa and adult. From the day the egg is laid to the day the adult chews its way out of the cell, it takes about 16 days for a queen, 21 days for a worker and 24 days for a drone. Once adult, a worker reared in summer lives about five to seven weeks, while one reared in autumn can live for several months and carry the colony through the British winter.

These numbers are the clock behind almost every decision at the hive: how long a queenless colony takes to recover, when an artificial swarm will have laying queens again, why a varroa treatment applied in October is too late, and why a colony full of stores can still die in February.

What are the four stages of the honey bee life cycle?

The honey bee (Apis mellifera) undergoes complete metamorphosis, like butterflies and beetles. The larva looks nothing like the adult: it is a white, legless, eyeless grub whose only job is to eat and grow. All the reorganisation into a flying insect happens later, hidden under a wax capping.

Egg: three days

The queen lays one egg at the base of each cell, glued by one end. It is 1 to 1.5 mm long according to the University of Florida, white and slightly curved, like a tiny grain of rice. Penn State’s Field Guide to Honey Bees and Their Maladies describes how its angle changes: freshly laid, it stands upright on the base of the cell, then gradually tilts over three days until it lies flat just before hatching. With a good light and a little practice, the angle of the eggs tells you roughly when the queen was last on that frame.

Whatever the caste, the egg hatches after about three days. That is why “eggs present” at an inspection means the colony had a laying queen within the last three days, which is the single most useful observation you can make.

Larva: about six days of explosive growth

The larva hatches on day 4 and lies curled in a pool of food deposited by nurse bees. It grows at a remarkable rate, moulting several times as it outgrows its skin. According to the North Central SARE life cycle sheet, the larval stage is a little shorter for the queen and a little longer for the drone than for the worker.

When the larva fills its cell, workers seal it with a porous wax capping. SARE puts capping at about day 8 after laying for a queen, day 9 for a worker and day 10 for a drone. From then on it is sealed (capped) brood, as opposed to open brood, which means eggs and uncapped larvae.

Pupa: metamorphosis under the capping

Once sealed in, the larva stretches out lengthwise, spins a silk cocoon against the cell walls and becomes a prepupa, then a pupa. This is metamorphosis proper. Larval tissues are largely broken down and rebuilt into the head, compound eyes, antennae, mouthparts, three pairs of legs and two pairs of wings. As in other insects, the moults and the metamorphic moult are driven by steroid hormones, the ecdysteroids. A Brazilian team (Mello and colleagues, Frontiers in Genetics, 2014) notes that in the honey bee their level in the haemolymph peaks during the pupal stage, while adult structures are forming.

The pupa starts pure white and darkens in a set order. Penn State’s field guide explains that the eyes colour first, going from white to pink, then purple and finally brown, and only afterwards does the body darken. Researchers, Mello’s group among them, use this sequence to age pupae precisely. If you uncap a worker cell and find a pupa with purple eyes, she is a few days from emerging.

Adult: emergence

At the end of the pupal stage, the adult, or imago, cuts around the capping with its mandibles and climbs out. It will not grow any more: a bee is full size the day it emerges. Newly emerged workers are pale, fluffy and slightly unsteady.

How long does each caste take to develop?

The stage lengths below are those given by the University of Florida’s IFAS Extension (Mortensen, Schmehl and Ellis), and the capping days come from the North Central SARE sheet. Capping days are counted from the day the egg was laid. The “sealed” column covers the whole time under the capping, including cocoon spinning and the prepupa. The BBKA Basic Assessment syllabus covers the bee life cycle, so this table is worth learning.

Caste	Egg	Larva	Capped on about	Sealed stage	Egg to adult
Queen	3 days	about 5.5 days	day 8	about 8 days	15 to 16 days
Worker	3 days	about 6 days	day 9	about 12 days	21 days
Drone	3 days	about 6.5 days	day 10	about 14.5 days	24 days

These are averages, not stopwatch times. They shift by a day or so with brood nest temperature, the strain of bee and nutrition. A queen sometimes emerges on day 15, and a drone can take a little longer than 24 days. Brood that has been chilled develops more slowly, which is one reason long inspections on a cold April morning are best avoided.

Worker development day by day

Because workers make up the bulk of the brood, it pays to know their timetable by heart:

1. Days 1 to 3: egg, upright at first, lying flat by day 3.
2. Day 4: the larva hatches into a film of food left by the nurses.
3. Days 4 to 6: fed generously on nurse gland secretions, then switched to a diet that includes honey and pollen.
4. Days 7 to 9: the larva fills the cell and is capped at around day 9.
5. Days 10 to 12: cocoon, prepupa and moult to pupa.
6. Days 12 to 20: pupa; eyes, then body, take on colour.
7. Day 21: the adult worker chews through her capping.

A frame of capped worker brood therefore holds bees that will all emerge within about twelve days; a frame of eggs will not add a single adult for nearly three weeks.

Why the queen develops so fast

The queen emerges about five days before a worker even though she is much bigger, because she is fed lavishly on royal jelly throughout her larval life. The drone, by contrast, has the longest development of all, mostly because of his two-week sealed stage. That long sealed stage matters to every British beekeeper because it is exactly what varroa exploits, as we will see below.

What decides whether a larva becomes a queen, worker or drone?

Sex depends on fertilisation

In honey bees, sex is set by whether the egg is fertilised. As she lays, the queen controls whether sperm stored in her spermatheca is released. A fertilised egg gives a female (worker or queen); an unfertilised egg gives a male. The queen measures cells with her front legs and lays fertilised eggs in worker cells and unfertilised eggs in the wider drone cells.

Strictly, femaleness depends on a single gene. Martin Beye’s group at Heinrich Heine University Düsseldorf describes how a bee that carries two different versions (alleles) of the complementary sex determiner gene develops as a female, while a bee with only one version develops as a male. Normally that means fertilised eggs give females and unfertilised ones give males. But when a queen has mated with drones closely related to her, some fertilised eggs carry two identical copies. They become diploid males, and workers remove them as young larvae. The result is the “pepper pot” brood pattern you sometimes see in inbred stock: scattered empty cells among the capped brood.

Worker cells on standard British foundation are a little over 5 mm across, and drone cells are noticeably larger. Bees build drone comb wherever they can, typically along the bottom bars and in corners of National brood frames, and drone cappings are domed rather than flat.

Caste depends on diet

A female larva becomes a queen or a worker depending on how she is housed and fed. A future queen is reared in a large, vertical, peanut-shaped queen cell and receives royal jelly throughout her development. A future worker gets nurse secretions at first and then a diet that includes honey and pollen.

A University of Illinois study published in Science Advances in 2015 showed that this is not just a matter of quantity. p-Coumaric acid, which is present in pollen and honey but not in royal jelly, changes the expression of a large share of the genome, including genes linked to the development of the ovaries, and pushes the larva towards becoming a worker.

This is what allows a colony to replace a lost queen. If she disappears, workers convert a few cells holding very young female larvae into emergency queen cells and flood them with royal jelly. The larvae must be young enough: one already well down the worker path makes a poor queen. For how the castes then share out the work, see our guide to the honey bee colony.

Why brood temperature matters during metamorphosis

Brood only develops properly within a narrow range of temperature. Jürgen Tautz’s team at the University of Würzburg notes that the air around brood combs always stays within about 33 to 36°C, though never at one constant value. Workers manage this by clustering on the combs, shivering their flight muscles to make heat, and fanning or bringing in water when it is too hot.

In a 2003 study in PNAS, the same team reared pupae at 32°C, 34.5°C and 36°C, all temperatures found naturally in hives. Nearly all of them emerged (98 to 100%), but the adults were not equal. Bees that had spent their pupal stage at 32°C performed only about 20% of the dance circuits of the others and disappeared from the colony sooner, while those reared at 36°C did best in tests of olfactory learning. In other words, the quality of metamorphosis shapes the behaviour of the adult.

Two practical points follow for a maritime climate where a spring day can swing from sunshine to a cold wind in an hour:

• Keep inspections short when it is cool. A brood frame held up in a breeze for several minutes loses heat fast. The National Bee Unit’s winter fact sheet advises opening hives on a day as warm and sunny as possible, ideally with bees flying, and never in cold, frosty weather; the same logic applies in spring.
• Think about the hive wall. The University of Leeds reports that Derek Mitchell’s work found that a typical hive with 19 mm wooden walls loses about seven times more heat than a natural nest in a tree hollow with 150 mm walls. Insulation over the crown board helps the cluster hold brood temperature in early spring, as does siting the hive out of frost pockets and prevailing winds (our guide to choosing an apiary site covers this).

Comb age plays a part too. Every generation leaves a cocoon and some faeces stuck to the cell walls, so old dark comb has slightly smaller cells. Replacing two or three brood combs a year in a National hive, for example with a Bailey comb change or a shook swarm, keeps cell size and comb hygiene in good order.

How long do honey bees live?

Lifespan depends first on caste, then on the season in which the bee is born.

Caste	Adult lifespan	Notes
Summer worker	about 5 to 7 weeks	worn out by brood rearing and foraging
Winter worker	several months, sometimes more than 280 days	reared from late summer into autumn
Drone	about 20 to 40 days	dies at mating or is evicted at the end of the season
Queen	several years	usually 1 to 2 years in managed colonies

The summer worker figure is SARE’s, which gives about five to seven weeks in summer and up to five or six months in winter. The drone figure, for unmated drones, comes from Juliana Rangel and Adrian Fisher’s review in Apidologie (2019). Brian Johnson’s 2010 review cites winter bees still foraging at more than 280 days old. For the queen, SARE notes that she can live several years but often only one to two in managed hives, where beekeepers replace her once her laying falls off; Simone-Finstrom and Tarpy write that a queen’s life can last upwards of two to three years.

What wears a worker out

It is not only foraging that shortens the life of a summer bee. In a 1966 paper in the Annales de l’Abeille, the forerunner of Apidologie, B. Roger and Janine Pain summarised Anna Maurizio’s experiments: in colonies with brood, summer bees lived at most about 60 days, but in broodless, queenless colonies their lifespan was measured at 167 to 188 days. Brood rearing, and the physiological drain of producing brood food, weighs heavily. Pollen, the colony’s protein source, lengthens the life of young bees, though the same paper notes that diet no longer changes longevity once a bee is past about 15 days old.

In British practice, a colony held back by a long spell of bad weather with little pollen coming in can dwindle faster than expected weeks later.

What jobs does a worker do as she ages?

A worker does not do the same work all her life. She follows a sequence tied to her age and to the development of her glands, which biologists call age polyethism. Brian Johnson’s 2010 review in Behavioral Ecology and Sociobiology sets out the main stages: the first few days are spent finishing maturation and cleaning cells, the nurse phase lasts about a week, roughly from day 4 to day 12, and the “middle-aged” phase runs from about day 12 to day 21.

Approximate age	Main task	What is happening in her body
1 to 3 days	cleaning cells	too immature to fly or sting
about 4 to 12 days	nurse: brood and queen	hypopharyngeal glands active, brood food production
about 12 to 21 days	comb building, receiving nectar, fanning, guarding	wax glands active
from about 3 weeks	forager: nectar, pollen, water, propolis	brood food glands regress

The timetable is flexible. Johnson shows that bees change role to suit the colony. If young bees run short, about 20% of foragers can regain the ability to feed brood. If foragers are lost, younger bees go out early. These switches are governed largely by juvenile hormone, which speeds up the move to foraging, and by vitellogenin, a storage protein abundant in nurses. The two move in opposite directions, and Johnson presents their mutual suppression as a hypothesis rather than a settled mechanism.

Foraging is the shortest and most dangerous phase: a few weeks at most, during which the bee works herself to death. How far she flies changes with the season. Margaret Couvillon, Roger Schürch and Francis Ratnieks at the University of Sussex decoded more than 5,000 waggle dances and found mean foraging distances of 493 m in spring, 2,156 m in summer and 1,275 m in autumn. Longer summer flights mean more wear on each forager, which is part of why the colony shrinks through the June gap and late summer dearth even when the queen is laying well.

Winter bees: how a worker lives for months

Bees reared from late summer into autumn, as the queen’s laying slows and forage dwindles, are physiologically different from their summer sisters. These winter bees carry the colony from October to March or April.

A body built to last

Mehmet Döke, Maryann Frazier and Christina Grozinger’s 2015 review in Current Opinion in Insect Science treats winter bees as a distinct physiological state, not just idle summer bees. Johnson describes it as low juvenile hormone, an active fat body, high vitellogenin and stronger immunity: a profile much like a nurse’s, but held for months. Döke and colleagues add that entering, keeping and leaving this winter state depends on environmental, physiological and social cues together.

With little or no brood to rear, these bees do not wear out. They form a cluster around the queen and make heat by shivering their flight muscles, burning stored honey. In late winter they restart brood rearing and feed the first spring generations, then die off over a few weeks. The colony’s lowest point in population is usually March, which is why a colony that looked strong in October can look alarmingly small at the first inspection.

British winters blur the line

The National Bee Unit’s winter fact sheet describes the textbook pattern: the queen stops laying in winter and resumes in spring. The UK’s mild, damp winters blur it. In mild southern and western districts and on the coast, colonies can keep a little brood late into autumn, with ivy flowering into November, and restart early after a mild spell. Further north and in upland Scotland the broodless period tends to be longer and more reliable. Where brood barely stops, the line between summer and winter bees is less sharp, and that small brood nest is also a refuge for varroa.

Stores matter because winter bees have to fuel the cluster. The National Bee Unit’s winter fact sheet says each colony should have approximately 20 kg of honey in autumn, topped up with winter-strength syrup if it has less; a full super holds at least 12 kg. Native-type dark bees (Apis mellifera mellifera) are often noted for frugal wintering, while larger Buckfast or Italian-type colonies may need the top of that range.

Why August decides the winter

The success of wintering is settled at the end of summer, when the long-lived bees are being reared: the NBU’s winter fact sheet places their development in late August and early September, and warns that heavy varroa infestation then can shorten their lives. A bee parasitised by varroa as a pupa does not develop the reserves she needs to overwinter and dies early. So in the UK, varroa treatment after the honey comes off in August is aimed at protecting the pupae that will become winter bees. Treat in October and those bees have already been damaged. Our page on varroa mites covers monitoring and the VMD-authorised treatments.

Queens and drones: maturity, mating and the end of life

The virgin queen and her mating flights

A virgin queen emerges from her cell on about day 16. She first seeks out and kills any rivals, then makes orientation flights before her mating flights. SARE puts these a few days after emergence, typically within the first week; in the North Carolina study below, queens were first seen flying seven days after emerging. She mates on the wing, away from the apiary, with drones from other colonies.

Michael Simone-Finstrom and David Tarpy’s 2018 USDA study gives a precise picture of this period. Of 80 queens observed, 65% began laying after a single successful mating flight, while the other 35% tried to fly again the next day. Queens mated with between 8 and 25 drones, 13.5 on average. Rangel and Fisher cite an average of 12 to 14 drones per queen, with cases of more than 50. Citing earlier work, Simone-Finstrom and Tarpy note that a fully mated queen typically stores 5 to 7 million sperm in her spermatheca, a supply she uses for life without ever mating again.

Laying starts a few days after the last mating flight, usually within about two weeks of emergence. Mating needs warm, settled weather. The University of Florida notes that all mating happens in the first two weeks of a queen’s life, so in a cold, wet British June a virgin kept indoors by the weather may never mate properly and can become a drone layer. At the spring peak a good queen can lay up to about 1,500 eggs a day, according to the same source. Add 21 days of worker development, and it takes about a month, often a little more, from a queen’s emergence to the emergence of her first daughters. More on this in our guide to the queen bee.

The drone: a life devoted to mating

The drone emerges on about day 24. He has no sting and no pollen baskets, and his large eyes meet at the top of his head. He is not fertile straight away. Rangel and Fisher report that orientation flights begin about five to eight days after emergence and that sexual maturity is reached, depending on the study, between 6 and 16 days, or at 16 to 18 days according to more recent work.

The same review describes drone congregation areas: 30 to 200 m across, 10 to 40 m above the ground, where up to 11,000 drones from as many as 240 colonies may gather. A drone that mates dies at once. Unmated drones usually live 20 to 40 days, and Rangel and Fisher note that eviction comes in autumn at the end of the reproductive season, which in most of the UK means from late August onwards.

Using the life cycle at the hive

Timings worth knowing by heart

• Queenless colony: an emergency queen reared from a one-day-old larva emerges about 12 days later. She then needs one to two weeks to mate and start laying, and her first workers take a further 21 days. Allow roughly six weeks from losing a queen to the first new workers, during which the population only falls. Do not give up on a colony with sealed queen cells after a week; wait at least three weeks before looking for eggs.
• Artificial swarm or split: the queenless half has no new bees emerging for about a month after its new queen emerges. A prime swarm that leaves with the old, mated queen starts laying again as soon as it has drawn some comb.
• Swarm prevention: queen cells with eggs or young larvae mean the colony is preparing to swarm. A cell is capped on about day 8 and a prime swarm usually leaves around the time the first cells are capped, which is why seven-day inspection intervals are standard in the UK swarming season from late April to July. See our guide to swarming.
• Drone brood in worker cells: domed cappings scattered across worker comb mean unfertilised eggs, so either an unmated or failing queen, or laying workers. Several eggs per cell, often on the side walls rather than the base, point to laying workers. The University of Georgia’s honey bee programme notes that laying workers rarely accept a new queen, which is why prompt requeening of a queenless colony matters; once laying workers are established, many beekeepers unite the colony with a queenright one instead.
• Winter: the bees that will see the colony through to spring are reared from August onwards. They must be raised in a healthy colony with good pollen coming in.

What the law expects you to notice

Reading brood is also how you spot the diseases you are legally obliged to report. American foulbrood and European foulbrood both kill the developing brood, and both are notifiable. The National Bee Unit makes clear that a suspicion must be reported: to the NBU or your local bee inspector in England and Wales, to the Scottish Government’s Bee Inspectors in Scotland, and to DAERA in Northern Ireland. Since 21 April 2021 the presence of varroa must also be reported in England, Wales and Scotland, which you can do through BeeBase; the duty does not apply in Northern Ireland. Registering on BeeBase is voluntary, free and the way inspectors find you if there is an outbreak nearby. The BBKA Basic Assessment, open to beekeepers who have managed at least one colony for 12 months, covers the bee life cycle. The NBU’s foulbrood guidance and your regional bee inspector can help you tell healthy brood from diseased brood.

How does varroa use the brood cycle?

Varroa reproduces only in capped brood. A mated female mite slips into a cell shortly before it is capped, hides in the brood food under the larva, then lays her eggs once the cell is sealed. Her offspring feed on the developing pupa and mate inside the cell; the mated daughters leave when the bee emerges.

That is why the drone’s long sealed stage is so important. The National Bee Unit’s fact sheet on drone brood removal (September 2026) explains that drone brood has the longest post-capping period, which lets the mite raise more mature daughters, and estimates that drone brood attracts on average eight times more mites than worker brood. Swiss researchers at Agroscope had put the preference at 8.3 to 8.6 times in earlier studies.

The NBU method turns this preference into a trap:

1. From May to July, while colonies are rearing drones, take out one empty brood comb next to the brood nest and replace it with a brood frame fitted with drone foundation or, more simply, a shallow super frame. On a National hive, bees build drone comb hanging below the bottom bar of the shallow frame.
2. The queen lays drone eggs in the new comb and mites move in before the cells are capped, at about day 10.
3. Around day 18, uncap some cells with an uncapping fork to judge the mite load.
4. Remove and destroy the sealed drone brood before day 24, by freezing or burning. On a super frame, cut off the drone comb and return the frame.
5. Dispose of it properly: brood left lying in the apiary can start robbing.

The NBU estimates each removal cuts mites by about 40 to 50%, that June and July are the most effective months, and that combining drone brood removal with a broodless period can reduce the mite population by about 90%. It is one tool in integrated pest management, not a treatment on its own: Agroscope points out that in spring a colony rears about ten times more worker brood than drone brood, and varroa breeds there too. Small colonies, or colonies with no nectar flow, may not draw the frame at all.

For the season-by-season picture of when each of these timings comes into play, from the first pollen in February to mouse guards in October, see our beekeeping calendar, and for anatomy and the senses, the bee biology section.

Frequently asked questions

How long do honey bees live?

It depends on caste and season. A worker reared in spring or summer usually lives about five to seven weeks, worn out by brood rearing and foraging. Workers reared in late summer and autumn become winter bees and live for months, some for more than 280 days. Drones usually live 20 to 40 days. A queen can live several years, though in managed colonies she usually lasts one to two.

How many days does it take for a bee to hatch?

From egg to adult it takes about 15 to 16 days for a queen, 21 days for a worker and 24 days for a drone. All three castes spend three days as an egg. The difference lies mainly in the sealed stage under the wax capping, which lasts about eight days for a queen, twelve for a worker and fourteen and a half for a drone. Cool brood develops more slowly.

What are the four stages of the bee life cycle?

Honey bees go through complete metamorphosis: egg, larva, pupa and adult. The queen lays the egg at the base of a cell, nurse bees feed the larva for about six days, the cell is then capped and the pupa transforms inside it, and finally the adult chews through the capping. At an inspection you can see eggs and larvae, but pupae stay hidden under the wax.

Why do winter bees live so much longer?

Bees reared in autumn raise little or no brood and barely forage, so they do not wear themselves out. They keep large fat bodies and high levels of vitellogenin, a storage protein linked to long life, with low juvenile hormone. That economy lets them cluster for months over a British winter, keep the queen warm and raise the first spring brood.

Can a worker bee become a queen?

An adult worker cannot. A very young female larva still can: if the workers build a queen cell around it and feed it only royal jelly, it develops into a queen. That is how a queenless colony makes emergency queen cells, provided it still has young larvae from fertilised eggs. Larvae more than about three days old make poor queens.

Why are drones thrown out of the hive in autumn?

Drones exist only to mate. They do not forage, make wax or feed brood, and they eat stores. When the mating season ends and forage dries up, usually from late August into October in the UK, workers stop feeding them, drag them out and refuse them entry. Outside, they soon die of cold and hunger. Queenless colonies often keep drones longer.

At what age do bees start foraging?

A worker usually starts foraging at about three weeks old, after cleaning cells, nursing brood and working as a builder, store keeper or guard. The order is flexible. If foragers are lost, younger bees go out earlier, and if nurses run short, some foragers can revert to feeding brood. Foraging lasts only a few weeks before the bee dies.

How can I tell how old brood is at an inspection?

Look at the eggs and the cappings. A freshly laid egg stands upright and slowly tilts over three days until it lies flat. Small larvae curled in a pool of food are a few days old. Worker cells are capped at about day 9, so capped worker brood will emerge within about twelve days. Drone cappings are domed and stand proud of the comb.

Sources

1. The life cycle of honey bees, North Central SARE, USDA National Institute of Food and Agriculture
2. European Honey Bee, Apis mellifera Linnaeus and subspecies (EENY-568/IN1005), Ashley N. Mortensen, Daniel R. Schmehl and Jamie Ellis, University of Florida IFAS Extension
3. A Field Guide to Honey Bees and Their Maladies (2011), Maryann Frazier, Dewey Caron and Dennis vanEngelsdorp, Pennsylvania State University, MAAREC
4. Developmental regulation of ecdysone receptor (EcR) and EcR-controlled gene expression during pharate-adult development of honeybees (Frontiers in Genetics, 2014), Tathyana R. P. Mello, Klaus Hartfelder, Zilá L. P. Simões et al., University of São Paulo
5. Behavioral performance in adult honey bees is influenced by the temperature experienced during their pupal development (PNAS, 2003), Jürgen Tautz et al., Proceedings of the National Academy of Sciences, via PubMed Central
6. Study identifies chemical in diet that determines a honey bee's caste (Science Advances, 2015), University of Illinois News Bureau
7. Haplodiploidy and complementary sex determination, Heinrich Heine University Düsseldorf, Institute of Evolutionary Genetics (Martin Beye)
8. Division of labor in honeybees: form, function, and proximate mechanisms (Behavioral Ecology and Sociobiology, 2010), Brian R. Johnson, Springer, via PubMed Central
9. L'influence de la reine d'abeille sur le taux de mortalité des ouvrières accompagnatrices (Annales de l'Abeille, 1966), B. Roger and Janine Pain, INRA, Apidologie
10. Overwintering honey bees: biology and management (Current Opinion in Insect Science, 2015), Mehmet Ali Döke, Maryann Frazier and Christina M. Grozinger, Penn State University
11. Factors affecting the reproductive health of honey bee (Apis mellifera) drones: a review (Apidologie, 2019), Juliana Rangel and Adrian Fisher II, Springer
12. Honey Bee Queens Do Not Count Mates to Assess their Mating Success (Journal of Insect Behavior, 2018), Michael Simone-Finstrom and David R. Tarpy, USDA-ARS
13. Honey bee disorders: non-infectious diseases and pests, University of Georgia, Honey Bee Program
14. Using Drone Brood Removal as a Varroa Control (Fact sheet 26, September 2026), Animal and Plant Health Agency, National Bee Unit
15. Le retrait du couvain de mâles operculé : une mesure efficace pour diminuer l'infestation de varroa dans les colonies (1998), Swiss Bee Research Centre, Agroscope
16. Preparing your hives for winter (Fact sheet 19), Animal and Plant Health Agency, National Bee Unit
17. Research challenges beliefs on honeybee insulation (work of Derek Mitchell), University of Leeds
18. Waggle dance distances as integrative indicators of seasonal foraging challenges (Couvillon, Schürch and Ratnieks, PLoS ONE, 2014), University of Sussex
19. Legal responsibility of beekeepers, Animal and Plant Health Agency, National Bee Unit (BeeBase)
20. Basic Assessment, British Beekeepers Association