1. Which race?

We are often asked why the breeding instructors of French-speaking Switzerland work with only one race (Carnica), why not another one, and why not several. In this article, we will briefly answer these questions and thus clarify an area of uncertainty for many beekeepers.

Before the arrival of modern beekeeping (movable-frame hives, around the 1800s), bees lived quietly in their native region and had been adapting to their local environment for millions of years. This natural selection led to the creation of specific ecotypes depending on a species’ adaptation to its environment. These are the subspecies that, in beekeeping, we call bee races.

The best known around us are:

• Apis mellifera mellifera (the dark bee, also called Nigra);
• Apis mellifera ligustica (the Ligustica, also called the Italian bee);
• Apis mellifera carnica (the Carnica, also called the grey bee).

Each of these races has developed particular characteristics. For example, Ligustica stores few reserves for winter and goes through winter with a large population. The dark bee and the Carnica, by contrast, go through winter with large reserves and a small population, which makes overwintering easier in cold areas.

Modern beekeeping has developed breeding methods and has enabled humans to do as in livestock breeding or agriculture:  cross subspecies in order to create new ones (e.g. Africanized bee). However, these crosses have only rarely brought positive results because, by diluting the characteristics anchored in the genes of the different races, a host of defects appeared:  aggressiveness, low disease resistance, poor yields. And, because of the bees’ mode of reproduction (the queen is fertilized by about fifteen drones), these undesirable traits rapidly spread in nature. To such an extent that the Société romande d’apiculture (SAR) appealed to the Federal Council to set up a working group whose objective was to combat this hybridization problem. This working group showed that the only solution was to return to a purebred bee. The problem was that the local bee had already been hybridized almost completely, so it was decided not to continue with that race (see genomic past of the Swiss bee). After testing five subspecies in different apiaries, this working group decided to use Carnica.

For more than seventy years now, the SAR breeding commission, in partnership with the groups of breeding instructors in the French-speaking cantons, has worked tirelessly to maintain the purity of this race, improve it (especially in terms of disease resistance), and make it available to every beekeeper. We will discuss in detail the work carried out by the breeding instructors in upcoming articles.

In conclusion, the choice to maintain a pure race and to work with a single race did not come out of nowhere. It was in response to a drift in beekeeping that we had to react, and since then we have been striving to maintain the quality of these bees. As for the question of why not use several bee races in one region, it is now clear that this would create a serious hybridization problem that would return us to the same catastrophic situation as at the beginning of the twentieth century.

2. Bee genetics

This month, we are going to look at bee genetics. Without going too far into detail, we will try to summarize its basic principles and their implications for selection. Interested readers will find more information online.

As you know, a bee colony is made up of a queen, workers, and a few males, called drones. Their respective developmental processes are very different.

The queen can choose whether or not to fertilize the egg she lays. A fertilized egg will produce a female, an unfertilized egg a male. After 3 days, the egg hatches. It is the food provided afterwards that determines whether a fertilized egg becomes a worker or a queen.

A larva destined to become a queen is fed only with royal jelly until the cell is capped (day 9 after egg laying). On day 16, the young queen emerges. After a few days, she will leave the hive to be fertilized by 10 to 25 males from other colonies, thereby ensuring the genetic diversity of her offspring.

The worker larva, for its part, is fed brood food for 3 days, then honey and pollen. During the 3 days when it is fed brood food, the female larva can still become a queen if the bees decide to give it royal jelly (for example if they have lost their queen in the meantime and must therefore produce a new one). This is the phenomenon used in queen rearing by giving very young larvae to queenless bees.

Drone larvae are fed in the same way as worker larvae. However, as stated above, the male comes from an unfertilized egg, which is a particularity in bees. Queens and workers have 32 chromosomes, 16 from the mother and 16 from the father. They are diploid like most animals and plants. Drones, by contrast, have only 16 chromosomes originating solely from the mother. They are haploid:  each chromosome is present in only a single copy inherited exclusively from the mother. Consequently, the spermatozoa of one and the same male are all strictly identical; they are clones, unlike the queen’s eggs, which are all different:  each egg is a unique combination of the various genes of the queen and the father.

 

In a hive, we therefore have a queen that has been fertilized by several males (shown in blue, yellow, red and green in the illustration below). The sons inherit only their mother’s genetic heritage. The daughters are half-sisters or super-sisters. Half-sisters do not have the same father. Super-sisters have the same father and, because the male is haploid, they have received from him exactly the same genetic heritage.

 

Thus, only the mother’s genetics are transmitted to the males, and these males retransmit them entirely when they mate with a young queen. Our selection programme is based on this specificity in order to disseminate the best possible genetics in the mating stations. In each A mating station, the males are all grandsons of a queen awarded in the selection programme (test apiaries). This makes it possible to have the same genetic pool in a given mating station, to control inbreeding, and thus to manage crosses between lines while respecting genetic diversity. We will return to these points in greater detail in future issues.

3. The purity of the Carnica race

As already explained in the previous chapters, the primary objective of SAR breeding is to preserve the purity of the Carnica race chosen by Liebefeld. How do the breeding instructors (MEs) measure this purity (or rather the absence of hybridization)? Is this work, carried out over decades, effective? What are the prospects for simplifying the work of the MEs? That is the menu of today’s article.

From the beginning of SAR breeding, the only means used by scientists to determine the race of a bee (subspecies) was morphological measurement. Several criteria are found in the literature:  cubital index, discoidal shift, tomentum width, tongue length, abdominal coloration, etc.

 

In Europe, the most widespread criterion is the cubital index. It is easy to measure and makes it possible to distinguish hybridization with Ligustica (Italian bee) and Mellifera (dark bee). The cubital index is the ratio between the lengths of segments “a” and “b” of the forewing:

 

Average cubital index values in Switzerland:

• Carnica : 2.3 – 3.2
• Ligustica : 2.0 – 2.7
• Mellifera : 1.4 – 2.1

In order to be certain of having no crossing with the two other races, the MEs set the cubital index criterion at a minimum value of 2.8 for our Carnica selection. We quickly introduced an additional criterion because almost all our queens met these criteria and we wanted to improve the precision of our selection. This is how the tongue-length criterion was introduced.

Each queen that an ME breeder wishes to use for breeding must reach this value. It is thanks to this strict threshold that we have been able to maintain the purity of our bees for so many years. Each year, the ME must take a series of bees from the colony to be analysed and send this sample to the laboratory. The laboratory measures the wing and tongue of around fifteen bees and gives an average value for the cubital index and tongue length. If all these criteria reach the extremely high level required, the ME will be able to breed from this queen and continue the selection process. This high level of selection has kept out all hybridization for more than seventy years.

For about the last ten years, we have also been using genetic analyses to verify whether our way of working is correct and whether there is indeed no hybridization within our lines, but also to verify the safety of the mating stations. This tool, although more complex, will probably in the near future allow us to limit the number of morphological measurements and thus simplify the work of the MEs.

As you understand, guaranteeing the purity of our stock is a long-term task that must be repeated year after year; otherwise, the characteristics naturally present in our Carnica bee would be diluted and lost in hybrid bees.

Back-up :

To calculate the cubital index, one measures on 100 different right forewings of workers the two vein segments forming an obtuse angle at the rear base of the third cubital cell, and establishes the ratio segment a/segment b.

The discoidal shift index is measured on the veins of a worker’s forewing by drawing a straight line joining the 2 ends of the radial cell. Then a line perpendicular to the first is drawn through the intersection of the veins of the radial cell and the 3rd cubital cell.

 

If this straight line passes through point A or to the left (proximally) of it, one speaks of negative discoidal shift and therefore of an A.m.mellifera. Conversely, if this straight line passes to the right (distally) of point A, one speaks of positive discoidal shift and therefore of an A.m.carnica.

 

Measurement of tomentum width (hair zone) is carried out on the 4th tergite (dorsal segment of the abdomen) and corresponds to the width of the hair on this segment.

4. Selection criteria

What a pleasure it is to work with gentle and productive bees. Is that not every beekeeper’s goal? Obtaining and, above all, maintaining these characteristics in a bee population does not happen by itself. This is why every queen breeding programme must be based on sound evaluations. In this February column, we present the selection criteria adopted by the SAR breeding commission (CE-SAR) for the Carnica race.

The CE-SAR selection criteria were initially 5 in number:  gentleness, frame steadiness, swarming resistance, disease resistance, and honey yield. They were recently supplemented by 3 new criteria:  colony strength at the start of overwintering, overwintering, and spring development.

Each of these criteria is based on a measurement scale common to all breeders.

• For gentleness, there must be no flying up, no attack, and no stinging in order to obtain the maximum score. This evaluation is complemented by frame steadiness, namely the absence of clustering and movement on the frame. These two criteria must be evaluated over at least 4 inspections, and the average is then calculated.
• Swarming resistance is measured every 5 to 9 days during the swarming period. The maximum score can be given if there is no sign of swarming:  no empty or laid queen cells.
• To evaluate disease resistance, hygienic behaviour is assessed using the pin test:  50 cells of sealed brood are pierced with a needle (pupal stage from pink-eyed to light brown); after 8 to 12 hours, the percentage of cleaned cells is counted.
• Honey yield is the easiest criterion to measure, using the weight difference between a full and empty super.

3 new criteria were introduced with the aim of selecting colonies that tend to become productive quickly in spring. For this, the colony must be strong at the start of overwintering, with good laying in September and many emerging bees. After overwintering, at cherry blossom, the colony must have at least 5 occupied seams and be clean (no dysentery, bottom well cleaned by the bees). Spring development is then assessed during the next 3 inspections. It is optimal if the brood is distributed regularly according to age and if the colony quickly builds the foundation, increases the population exponentially, and is ready when the supers are placed.

And what about Varroa resistance? Can it be used as a selection criterion? How? To date, unfortunately, there is still no clear answer to this question. Within SAR selection, we try to identify the colonies with the fewest Varroa mites in order to take that into account. However, there is no scientific proof of the heritability of such resistance or of related behaviours. Moreover, a low Varroa load is not necessarily due to the colony’s behaviour;  it may also be the result of environmental conditions, especially the absence of infested hives nearby.

The criterion of Varroa resistance is therefore the most complex to develop. Let us hope that it will soon be possible to identify resistance behaviours that are transmitted by heredity. In any case, selection must continue according to the various other criteria presented above in order to continue benefiting from gentle and productive bees.

5. How to control the origin of male genes

In any breeding programme, in order to cross and transmit very specific traits, it is necessary to control where the carriers of male and female genes come from. In most farm animals, this is fairly simple because one male fertilizes one female. Crosses can easily be controlled. In the honey bee, however, the story is completely different because of polyandry. The female is fertilized by a multitude of males (about fifteen). How, then, can the origin of male genes in bees be controlled in order to determine crosses precisely?

There are two methods to overcome this difficulty:

1. Artificial insemination

This procedure makes it possible, with the help of a microscope and drone sperm, to fertilize the queen. This technique makes it possible to be 100% certain of the mating, but it is difficult, remains reserved for a few people, and gives a success rate of about 80% even for experts. Only a small number of queens can be fertilized in this way, which does not allow the selected genetics to be disseminated widely by breeders.

2. Mating stations

Another solution is to isolate, in a remote place, the queens to be fertilized together with a series of male lines containing only brothers from the same family. The particular topography of the Alps makes it possible, in remote valleys, to isolate this group of bees and thus protect it from the arrival of unwanted males. These stations are a wonderful working tool for breeders because they allow a large number of queens to be naturally fertilized (propagation of genetics) with a technical level that is easily accessible to any beekeeper. These stations are protected by cantonal agricultural law;  it is therefore forbidden to place hives within a perimeter of about 6 km around the station in order to avoid any genetic pollution.

 

Valais has three stations managed by SAR breeding instructors: Bonatchiesse (reserved for breeding instructors), located at the foot of the Mauvoisin dam Les Toules, located at the foot of the Les Toules dam Moiry, located at the foot of the Moiry dam (see photo)

 

Valais breeding instructors work tirelessly to enable all beekeepers to benefit each year from the genetics of the lines of the SAR breeding commission (CE-SAR). One line is present for two consecutive years in the same station. (Detailed information at https://favr.ch/elevage/stations-de-fecondation/)

If you too would like to benefit from these stations, we invite you to contact the breeding instructor of your local section or to take part in the breeding course in your region. This will allow you to rear from selected brood and obtain all the necessary information to bring your nucleus boxes to the station according to best practice.

 

6. Test apiaries

In the previous chapter, we presented the SAR mating stations and their role in selection. Thanks to the 6 SAR A stations, the purity of the Carnica race has been maintained for more than seventy years. We will now explain how the best genetics from our selection are made available in the stations.

It is thanks to the test apiaries that the best-performing queens are identified. Each year, between 10 and 15 test beekeepers, distributed throughout French-speaking Switzerland, receive 12 queens to test in July. They do not know from which lines these queens come. The test is therefore carried out as impartially as possible.

The testers introduce these queens into bee packages or standardized nuclei. These colonies are placed in the same apiary and cared for in the same way in order to avoid any bias. The testers evaluate them over the following 12 months, on the basis of the selection criteria presented in our article of last February:  gentleness, frame steadiness, swarming resistance, disease resistance, honey yield, etc.

All the testers’ evaluations are recorded in their test notebook and then transmitted to the SAR breeding commission. On this basis, a ranking of the tested lines is established. Three to four lines are awarded each year. The best queen of each awarded line is handed over to the managers of the drone colonies at the mating stations that need to renew their line. The same line remains in a station for a maximum of two years. 

The managers of the stations’ drone colonies then rear a large number of daughter queens from the awarded queen received. The objective is to have at least 40 colonies derived from the awarded queen so that, over the two following years, the 20 best colonies can be taken to the station. In spring, a drone frame is introduced so that these colonies contain as many mature drones as possible when the station opens.

 

Illustrative table:  example of a test apiary

 

There is thus, in each mating station, a specific genetic pool derived from a queen awarded in the test apiaries (see also our article from last December on bee genetics). The Beebreed database then makes it possible to calculate the inbreeding rate of this genetic pool in relation to the brood made available by the breeding instructors for your queen rearing. Beebreed also makes it possible to estimate the chances of improving one trait or another (gentleness, production, etc.) depending on the station chosen.

This year, the new lines made available in the Valais stations are SLO97 at Bonatchiesse and CC95 at Les Toules. At Moiry, we will find SM89 for the second year. Do not hesitate to drive a few extra kilometres to visit another SAR A station:  Hongrin (above Aigle VD), Petit-Mont (above Charmay FR), or Vermeilley (above Nyon VD). The breeding instructors are available to advise you in your choice.

 

7. Rearing for one’s own use

The month of May has arrived, and with it the swarming season is in full swing! Bees naturally rear new queens in order to divide the colony into two, or even several, swarms and thus ensure the survival of the population. Swarming is one of the three situations in which the hive will rear queens. In the case of supersedure or the sudden death of a queen, it will also rear them.

The breeder makes use of these natural predispositions while adding a few techniques to simplify and promote rearing for personal use. Humans become the trigger of the bees’ breeding work and guide it so as to be able, in the end, to recover several queens that can be used to replace ageing queens, form nuclei, or replace an unsatisfactory queen.

In this article, we will explain a simple method for obtaining several queens with a minimum of work and with a basic technical level. Next month, we will provide fuller information on a more advanced rearing method that makes it possible to obtain more queens and bring them to a mating station.        

First, since the aim is to obtain F1 queens (daughter queens of a pure F0 queen and mated in the apiary), we must have a good colony that is strong, healthy, and headed by an F0 queen. We must also prepare an empty 6-frame nucleus box.

We are going to make the mother colony queenless by taking 2 food frames, 2 frames of sealed brood, and 1 pollen frame, making sure to take the F0 queen as well. These frames are placed in the empty nucleus box, which is moved farther away in the apiary. Depending on the weather and nectar flow, the mother colony can be given a light stimulating syrup. It is important to check that there is fresh brood (egg laying or very young larvae) in the mother colony so that it can rear new queens properly.

2-3 hours later, this colony will naturally begin to rear a large number of queens. As early as the next day, one can observe a series of queen-cell starts filled with royal jelly.

6 days later, the cells will be capped and can be transferred into nuclei or previously populated mating nuclei. To cut out the queen cells for transfer, you can use a small knife whose blade you warm regularly with your soldering lamp. You can easily leave a good margin of wax around the cell. A toothpick can be used to fix the cell onto one of the frames in the nucleus. Giving a little syrup to our colonies, which will continue to care for the cells for another 6 days, is advisable. The queens should emerge about 12 days after the beginning of the operation. On day 13 or 14, one can check the opening of the queen cells. In case of a problem (if a queen has not emerged, for example), either one has another queen cell or queen at hand and can introduce it, or one can unite this nucleus with another. If they have emerged, it is enough to wait patiently a good 2 weeks for the queen to be fertilized and start laying.

On the internet and in the literature, one finds a whole series of variations of this method:  cutting the brood frame so that it is easier to cut out the cells, dividing the colony to make the method even simpler, though then no more than 1-2 nuclei can be made… It is up to you to try and find the method that suits you best.

8. Rearing with a “starter”

Like May, June is favourable for queen rearing. It is also the month when the mating stations open. In our May article, we presented a simple rearing method consisting of dividing a colony and then cutting out the queen cells for transfer into nuclei or mating nuclei. Today, we will present another method that makes it possible to rear more queens. We will also remind you of the rules to be respected when taking queens up to a mating station and the reasons behind them.

Rearing begins by making part of the hive queenless:  a “ starter ” is created. This must contain enough nurse bees, honey, pollen, water, and above all young larvae from a good F0 queen. In principle, the starter is created on a Friday afternoon or at the latest on a Saturday morning. In this way, one can go up to the mating station two weeks later (the stations being open on Saturdays).

A simple way of creating a starter is to remove the queen from a strong hive together with 3-4 frames of young brood (eggs and small larvae). The queen and the frames of young brood, together with the bees, are placed in a 6-frame nucleus box that can be left in the apiary or taken to another apiary. The rest of the hive constitutes the starter. Another way of creating a starter is to insert a sealed division board into the original hive or use a double hive:  on one side, the queen with the young brood, and on the other side, the rest of the colony (starter).

In both cases, one must ensure that there is as little young brood as possible in the starter. To do this, one can introduce a vertical queen excluder one week beforehand to avoid having young brood in the part that will become the future starter. There are several other methods for creating a starter that you can find on the internet or in volume 3 of L’Apiculture, une fascination.

The more nurse bees there are in the starter, the more queen cells there will be. Nurse bees generally stay on frames of young brood. You can strengthen your starter by taking a frame of young brood from another hive;  make sure the queen is not on that frame;  brush the bees into the starter;  then put the brood frame back into its original hive.

One to two hours later, young larvae must be introduced into the starter. To do this, you go to a breeding instructor with a grafting frame and new plastic cups. He will be able to graft young larvae from his best F0 queen. You can also do it yourself if you have previously trained in grafting (picking). The breeding instructor will also give you the declaration form for going up to the station, signed to certify the purity of the brood made available and thereby allowing you access to a SAR Carnica A mating station.

 

The grafting frame must then be wrapped in a damp cloth to prevent the larvae from drying out during transport. The grafting frame is then introduced into your starter. If you have taken your starter with you (or part of it in a swarm box, for example), you can introduce the grafting frame directly and take the whole lot back to your apiary. Feed your starter well if there is little natural input, especially at the beginning of the rearing phase, and even before.

24 hours later, you can open your starter to check the number of queen cells started. If necessary, you can go back to the breeding instructor for another grafting and introduce the cups into your starter to complete it.

5-6 days later, the queen cells will be capped. You can then place protective cages around the queen cells to prevent the first queen to emerge from destroying the others. Also take the opportunity to destroy any “ wild ” queen cells built on the other frames. It is important to place the protective cages at that time and not later, because the nymphs then enter a metamorphosis phase during which they become very sensitive to shocks and cold. The starter must therefore no longer be opened during the following days (days 7 to 9).

Meanwhile, or even before if you are well prepared, the mating nuclei must be prepared. The mini-frames must be fitted with a wax starter strip of foundation of about 1/3 of the height of the mini-frame. It is fixed by melting a little wax. Each mating nucleus must contain 3 mini-frames. The feeder is then filled with candy. This candy must not contain honey in order to prevent the transmission of diseases in the mating station (honey may contain foulbrood spores). Honey-free candy can be bought commercially or made at home (10 kg icing sugar, 3.8 kg invert syrup).

 

10 days after the creation of the starter, it is time to populate the mating nuclei. The bees are taken from various hives and/or from the breeder colony. They are sprayed with a little oxalic acid to avoid bringing Varroa mites into the mating stations. They are then gently brushed into a large funnel placed above a 6-frame nucleus box topped by a super, with a queen excluder between the two. The number of frames to brush depends on the number of mating nuclei to populate.

About one side of a frame is needed per nucleus. The bees are then gently pushed with a board and a little smoke toward the bottom of the super;  they thus pass through the queen excluder and settle in the 6-frame nucleus box. This makes it possible to filter out the drones:  they cannot pass through the queen excluder. They are released only once the mating nuclei have been populated. This avoids their ending up in the mating nuclei. These must absolutely be free of drones to avoid genetic pollution in the mating station.

 

To populate the mating nuclei, one takes the equivalent of one yoghurt cup of bees per nucleus. The mating nucleus is turned upside down, the bottom opened, and the bees poured in. Everything is then closed quickly without crushing bees. The nucleus is then turned upright again. These operations are easier when done by two people. The mating nuclei are then placed in a cool place (cellar). During the night, the bees will feel queenless. Thus, the next day, they will be ready to receive a new queen.

On day 11, the queen cells are taken from the starter and introduced into the mating nuclei. The queens will emerge on day 12 or 13. It is important then to leave the nuclei closed so that colony cohesion forms around the new queen during day 13 and day 14. On day 15, the nuclei can be taken to the mating station and nature can take its course. The nuclei will be collected two weeks later. Do not forget to contact the station manager before going there and to bring the declaration form for going up to the station.

 

The breeding calendar is an essential tool for planning breeding properly and intervening at the right time; otherwise, the breeding will fail. It is available in electronic version (xlsx). You can enter in cell D1 the desired date for going up to the station. Here is the calendar for our breeding course next 1 June.

 

You will find more details and information on this rearing method in the document “ Devenir Apiculteur Éleveur ” by Julien Balet, which you can download free of charge.

We wish you much enjoyment and every success with your breeding.

 

QR code breeding calendar

 

QR code Devenir Apiculteur Éleveur

 

9. Management of nuclei on return from the station and introduction of queens

At the station, by looking through the plexiglass of the nucleus, one can already see whether the combs are well built, sometimes even with construction in the feeder. The queen is probably there and laying. However, if the mini-frames are little built and there are few bees, there is probably no queen. She will have been lost during the mating flight or eaten by a bird.

On return from the station, the nuclei are placed at home or in the apiary, if possible not too exposed to the sun. The lightly populated nuclei are inspected first. If there is no laying, the mini-frames are little built, and there are drone cells, then there is no queen. The nucleus can then be emptied by brushing the bees outside. They will go and seek shelter in other hives or nuclei.

The other nuclei can then be inspected gently. Care must be taken not to frighten the young queens:  they might fly off and be lost. One must therefore proceed gently, lifting only the first mini-frame. If there is laying, everything is fine. One does not inspect further and closes the nucleus again.

Afterwards, remember to check that the nuclei have enough food. From mid-July onward, external intake decreases and the nuclei need to be refed with candy regularly:  check at least every 2 weeks.

Before taking a queen from a nucleus to introduce her into a hive, it is better to wait until the first daughters of that queen have emerged, or at least until there is capped brood in the nucleus. The queen will be more readily accepted than if she has only just started laying.

Be careful when taking the queen from the nucleus. She must not be frightened, otherwise she flies off and is lost. Aspiration queen-catching tubes are very practical, especially when the queen is not on a mini-frame and hides at the bottom of the nucleus. Once the queen has been taken, mark her and place her in a cage. If you are not introducing her the same day, add 3 bees to the cage to accompany her.

There are several methods for introducing queens. First of all, one must be sure that the colony is truly queenless. It may contain two queens if supersedure has taken place and the old queen is cohabiting with her daughter. In that case, if only the old queen is removed, the daughter remains and the station queen to be introduced will not be accepted. A good way to avoid this kind of mishap is to wait 7 to 9 days after removing the old queen before introducing the station queen. In this way, one can verify that queen cells are present, proof that the hive is indeed queenless and awaiting a new queen. The station queen can then be introduced in a cage closed with candy. You may destroy the queen cells, but this is not indispensable.

1 to 2 days after introducing the cage, it will be necessary to check that the queen has been able to come out. Sometimes the candy is too dry and the bees do not eat it. In that case, remove the larger part of the candy and replace the cage. Check the next day whether the queen has been able to come out. It is also possible to release the queen gently between two frames.

Then wait at least one week before checking acceptance of the queen. During this control visit, one must also proceed gently so as not to frighten the queen. Use no smoke or only very little. It is not necessary to see the queen. As soon as you observe fresh laying, everything is fine. You can calmly close the hive again.

 

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See also:

• Drone rearing – biology, genetics and beekeeping practices
• All about drones
• Drones – an indispensable luxury for the colony