Review of the queen bee instrumental insemination season 2021

August has arrived unnoticed and season of the bee queen insemination has ended successfully. This summer there was a great opportunity for beekeepers to inseminate queen bees all over Latvia. Although each of the beekeepers had certainly planned to produce their own drones in the spring, only a part of them managed to find time to produce the drones in the madness of seasonal work. Below I would like to tell you about our experience this season.

DRONES. Due to unfavorable weather conditions, in the spring we obtained the first frame full of drone cells and eggs only on May 12, so it was already known that we would start the instrumental insemination season on June 18. We inserted new frames for drone brood producing every 2 weeks to ensure continuous availability of the mature drones. With the last frame on June 25, it was more difficult, we had to force the queen bee to lay eggs using a queen isolator. We used both multi-hull hives and Latvian standing hives for drone rearing, in which the drones lived in two-frame isolators or in closed space using queen excluder. One week before the day of insemination, we installed additional space (drone flight cage) for both types of hives so that the drones could fly out and defecate. The drone flight cage is a box screwed from wooden slats, with a plywood floor with a 5 cm diameter hole drilled in the bottom, a queen excluder is used on one side to allow free movement of the worker bees, and the other walls are made with a hard insect sieve (see Figure 1).

On sunny days from 13-19 o’clock (activity peak was from 15-17 o’clock) there was an active flying and defecation of the drones, as a result the apiary was noisy and smelled with a not so pleasant aroma. In the evening, when the active flying and defecation calmed down, the drones successfully returned to the hive. Of course, some of the weakest drones also remained in the drone flight cage and froze.

When visiting other beekeepers, in addition to the drone cage, other methods used were the following: some of the drone flights were done in isolation in the forest, where there were no other bee colonies nearby; another method used was manual marking of the drones so they could live freely in the apiary.

BEE QUEENS. We started rearing bee queens 20 days after we noticed drone combs were full with eggs. We inseminated bee queens at different ages - 6 to 12 days old.

The used methods of storing the bee queens until the day of insemination were different:

• in a plastic tube in a queen bee nursery colony,
• in a wooden cage in a queen bee nursery colony,
• in a wooden cage in the nucleus/new swarm colony intended for the bee queen,
• the bee queen was born and freely inhabited the nucleus/new swarm colony.

I definitely do not recommend using plastic rollers and plastic cages for long-term storage of virgin bee queens, as so many bee queens had damaged legs or missing suction cups (which can only be seen under a microscope), which can be a reason for not accepting a bee queen later on after insemination. If it is not possible to prepare large quantities of nuclei/new swarm colonies at once, it is better to keep the queens in wooden cages on the nursery colony. Disadvantage – the bee queen will have to be added to a foreign nucleus/swarm colony after insemination. A good method is to keep the bee queen in a wooden cage in her intended nucleus, because worker bees that accepted her feed the bee queen. It is certainly more convenient and safer for the beekeeper to keep the bee queen this way so that she does not fly off, but the bee queens kept in this way will be smaller in size. Definitely, the best method is the birth of a bee queen and roaming freely in the nucleus. Such bee queens are considerably larger, livelier, and wake up very quickly after insemination procedures. Advantage - you won't have to worry about colony accepting the bee queen, disadvantage - the beekeeper will have to catch the bee queen for insemination so that she does not fly away, spraying the bee queen with water, painting the bee queen beforehand and the skill of the beekeeper will definitely help.

INSEMINATION PROCESS. On the agreed day of insemination, we went to the beekeepers with the insemination equipment. When going to the beekeeper, it is desirable to prepare a room for insemination, in which there is a freely accessible window, against which drones can fly and queens can be inspected, an electrical outlet and a sink are required. As the whole process (semen collection and insemination) was time consuming and we had to sit in one position for a long time, the height of the table and the comfort of the chairs were important, so we took care of it ourselves, taking the folding table and chairs with us.

The first task of the beekeeper on the day of insemination was to catch all the queen bees in plastic tubes, which we immediately treated with carbon dioxide for the first time for 6 minutes.  Then bee queens were returned to their original nuclei/swarm colonies. After that beekeeper brought the drones into the isolator or picked them from the colony and brought them into a wooden cage. We released drones to freely fly against the window and started collecting sperm.

Until noon, drones can be freely lifted out of the hive with frames and picked up or brought into the room with frames, as they are still calm and do not rush to fly. In the afternoon, during departure time, the drones must be picked up from the drone flight cage or carried indoors in a closed isolator so that they do fly off into the air.

The fastest, most convenient and cleanest sperm could be collected from drones that had flown freely in the apiary or taken to the forest, also acceptable drone quality was with drones that departed in the drone flight cage and more difficult and dirty sperm collection process was with the drones that were kept in the isolator without opportunity of daily departure. We also observed significant differences in stimulation of drones between bee races, accordingly, the easiest way to stimulate and collect sperm at any time of the day was from the Carpathian and Carnica drones, relatively easily it could also be done from the Buckfast drones, and from the Finnish-Italian drones it was possible only in the afternoon at natural drone departure time. Flying and defecation of drones, time and the race of the bees determine how easily, cleanly and quickly the required amount of semen will be collected.

When we collected the semen for all the bee queens, the beekeeper brought the first bee queen to the insemination room. During the insemination process, the bee queens were put to sleep for the second time for 6 minutes. After insemination, beekeeper placed the bee queen in paper sheet (5x5 cm) and carried to the prepared nucleus or swarm colony. We lightly sprayed bee queen with honey water so the worker bees cleaned her and the bee queen could run freely throughout the nest, which is very important for the first 40 hours after insemination because of semen migration into queen’s spermatheca. At the entrance of the nucleus or swarm colony, we attached a queen excluder, which had to be kept until the day the bee queen started laying eggs.

Both familiar and unfamiliar worker bees accepted inseminated bee queens. I can confirm that the method of adding bee queen directly into the nucleus or swarm colony by spraying it with honey water is very successful. For safety reasons, you can spray also the worker bees with honey water. By the time when the bees clean each other, the bee queen will be already accepted.

Of course, the nucleus or swarm colony must be prepared very carefully and responsibly before the bee queen is admitted, and all supersedure queen cells must be inspected and removed, ideally the nucleus contains only the sealed brood (so it must be prepared at least 9 days before insemination).

This summer, we used two different approaches to carbon dioxide treatment of queen bees. In June, we administered carbon dioxide treatment only once during the insemination process for 10 minutes, as a result of which the bee queens started laying 1 to 4 weeks later from the day of insemination. In July, we administered carbon dioxide treatment twice for 6 minutes, as a result of which 50% of the bee queens started laying within a week, the other 50% later - within 2-3 weeks. Regardless of the start of laying, all bee queens began to lay fertilized eggs. Definitely, after two shorter carbon dioxide treatments the bee queens wake up faster than after one long carbon dioxide treatment. The other disadvantages and advantages of both approaches will be shown by the time the bee queens are tested next season.

RESULTS. As a result of this season, we inseminated 194 bee queens instrumentally, both by insemination in our own apiary and by providing an insemination service. Of all inseminated queen bees, 57% were Buckfast, 19% Finnish-Italian, 15% Carnica-Carpathian, 9% Carnica. A variety of breeding material was used for insemination from Latvia, Germany, Denmark, Slovenia, Finland, Lithuania, Belarus and Russia. For the next season there will be material from other countries.

By the beginning of August, 108 bee queens are successfully inseminated and are laying fertilized eggs, the result is expected for some more bee queens. Unsuccessful insemination was found in only 6 bee queens who laid unfertilized eggs. We were also faced with many other factors and mistakes made by beekeepers, which reduced the total number of surviving bee queens. The most significant errors were the following: improperly prepared nucleus (created shortly before the bee queen was added, with many open broods, with supersedure queen cells, with another bee queen already present in the nucleus, with few worker bees, with laying worker bees, etc.), bee queen flew away during inspection, robbery of the nuclei (especially in the second half of July), failed acceptance of the bee queens by the colony, crushing or injuring the bee queen during the examination. All of the factors listed above can be prevented with careful and planned work by the beekeeper. In order to prevent robbery, certain nuclei must be taken further away from the apiary, with the robbery alone we lost 7 laying bee queens in our apiary.

Throughout the season, there was genuine concern about the outcome of each queen's insemination, and it was a great pleasure to inseminate bee queens who passed the laying test with excellence (see Figure 2).

The evaluation of this summer's work, the evaluation of the next generation and the development of the database will only start now. We are determined to continue working next year!