Instrumental insemination of bee queens, the first step – drone rearing

One of the highlights of this beekeeping season is the instrumental insemination of queen bees, which will enable beekeepers to introduce, improve and maintain the best characteristics of their bee colonies in the apiary, such as high productivity, the desired speed of development in spring, gentleness, hygiene behavior, etc. [1].

Instrumental insemination of queen bees is a controlled breeding method that results in the manual collection of semen from drones reared from a queen with good colony characteristics and administered to a virgin queen reared from another queen with the desired colony characteristics. The purpose of instrumental insemination is to ensure the refinement, development and preservation of desired colony characteristics and to engage in honey bee breeding work. Instrumental insemination avoids the mating of queen bees with drones of unknown origin, as is the case during natural insemination, so that the beekeeper has control over the preservation of the desired characteristics of the colonies, the elimination of undesirable characteristics and the introduction of new characteristics.

Maintenance of good characteristics of the colony can be ensured by either reared bee queens or drones. Since drones develop from an unfertilized egg, drone genes are a copy of the queens genes, and the drones ensure the continuation of the characteristics of their grandmother's colony. In order for instrumental insemination of queen bees to be possible, drones and queens must have reached sexual maturity on the day of insemination. The queen bee must be between 5 and 14 days old from birth [2]. The queen bees can be reared by the beekeeper him/herself or purchased from the queen breeder. A significant advantage of beekeeper’s reared bee queen is known characteristics of the bee colony, which can be continued, while the disadvantage is extra work.

The beekeeper must decide, according to their capabilities, whether to rear the bee queens themselves or to purchase it. The rearing of queen bees is widely described in the published materials [Büchler, R., Andonov, S., Bienefeld, K., Costa, C.,Hatjina, F., Kezic, N., ... & Wilde, J. (2013). Standard methods forrearing and selection of Apis mellifera queens. Journal of ApiculturalResearch, 52(1), 1-30.], therefore it will not be described in this article.

The preferred age for drones on the day of insemination is 38 to 44 days after the eggs are laid in the drone comb. By day 38, the drones reaches full sexual maturity, while the use of drones after day 44 reduces the quality of the semen to be collected, reduces the amount of semen migrating into the queen's spermathecae and increases the accumulation of semen in queen’s oviducts [3]. Therefore, the beekeeper must know the exact age of the drones, which is an important factor in the successful insemination of the queen bee.

It is necessary to prepare in time for a sufficient number of drones to reach sexual maturity on the day of insemination.  I'll give you an insight into one of the methods how to rear drones.

First. Choose the bee queen from which you want to rear drones. Take into account that the drones are copy of bee queen’s genes, but the characteristics of the transferred genes must be judged by the grandmother's colony. If the chosen bee queens are purchased from a queen breeder and the characteristics of the previous generation colonies are not known, the breeder may be asked about the characteristics of the colonies from which the queens are reared.

Secondly. Prepare a new frame for drone cell manufacturing. Use a standard size brood frame in which a cell strip approximately 2 cm wide is attached to the top of the frame or prepare the frame with full size artificial drone cell wax sheet [4], which can be purchased at beekeeping equipment stores. The prepared frame is placed in the selected breeding colony or other strong bee colony in the center of the nest so that the working bees produce full size wax comb with drone cells. If another bee colonies’ queen has managed to lay eggs in the drone cells, the frame is removed and placed in a bag and placed in the freezer for a few hours [4]. The frame is then allowed to thaw, sprayed with honey water or sugar water and placed in the selected bee colony. The worker bees will clean the cells, and the selected bee queen will lay eggs. In the first half of the season and during a good nectar yield, there should be no problems with egg laying. If there are problems with egg laying, then bee colony can be stimulated by feeding them honey or 200-400 g of sugar syrup prepared in a 1: 1 ratio [5]. Alternatively, the bee queen with a frame can be placed in an isolator made of queen excluder [6]. The work should be planned so that the bee queen can lay drone cells approximately 40 days before the planned instrumental insemination of the queen bees.

Third. In order not to weaken the selected bee colony, the care of the drone brood can be entrusted to a prepared another bee colony. While the queen bee is laying drone cells, prepare carrying bee colony, which will be populated in two level hulls of beehive. For drone rearing process you can choose bee colony with swarm tendency, queenless or with virgin queen. In beehive between hulls (levels) you have to place queen excluder so that only working bees move to the upper level. In the upper level open and sealed working bees broods (cut out drone brood) and feed frames are placed. The day before the insertion of the desired drone comb and also after that, the bee colony is stimulated with sugar syrup and pollen if there is no yield in nature. The frame of the drone brood is transferred to the prepared bee colony only after hatching, from day 4, so that the new bee colony does not clean the drone cells from eggs [6]. In order for the bee colony to take good care of the drone broods, it must create a brood care mood at all times.

Fourth. Drones are born on the 24th day after laid eggs, after which they have to wait for the day of insemination. In order for the drones to remain viable and to be able to fly and defecate, on the side of the upper hull or in the roof is required a hole of which a cage of metal sieve or other material shall be attached. The advantage of such a cage is the possibility for the drones to fly, defecate, which will increase the viability of the drones, reduce the defecation in the hive and the possibility of contaminating the semen during insemination, and the drones are still in an enclosed space, which guarantees known origin.

The second option is to paint newly born drones the same way we do to queen bees, in which case the queen excluder can be removed from the hive and the drones can inhabit the entire nest and fly freely in the apiary. The advantage is the possibility of the drones flying and free movement in the hive, as well as the known origin of the drones, while the disadvantage is that a reserve of 30 drones per bee queen is required, so the painting will be time consuming [6].

The third option is to place the frame of the brood in an isolator a few days before birth (isolator is cage of 1-3 frames with the sides made of a sieve or queen excluder), where they are born and live until the day of insemination [4]. The advantage - the origin of the drones will be known, the disadvantage - the drones will not fly and some of them may die.

If the beekeeper does not care about 100% of the known origins of the drones, then the drone can be allowed to be born in hive without queen excluder. If the bee colony is well prepared, then most drones will not leave it, but there is a possibility that some other drones form other colonies also want to live in this prepared colony.

The solutions for producing the drones, ensuring control over their origin and maintaining the drones until the day of insemination must be chosen and adapted by the beekeeper.

References:

• [1] Oxley, P. R., & Oldroyd, B. P. (2010). The genetic architecture of honeybee breeding. Advances in insect physiology, 39, 83-118.

• [2] Cobey, S. W., Tarpy, D. R., & Woyke, J. (2013). Standard methods for instrumental insemination of Apis mellifera queens. Journal of Apicultural Research, 52 (4), 1-18.

• [3] Woyke, J., & Jasinski, Z. (1978). Influence of age of drones on the results of instrumental insemination of honeybee queens. Apidologie, 9 (3), 203-212.

• [4] Brausse J. (2018). Drone producing in time. Millers A. translation. Available: https://buckfast.lv/

• [5] Šteiselis J. (2016). Bee queen rearing. Publisher: Latvian Beekeeping Association

• [6] Brusbārdis V. (2017). Artificial insemination of queen bees. Publisher: Latvian Beekeeping Association