Queen breeding
Breeding and selection.
We are using approximately 200 colonies for the selection of new breeder queens. All potential breeder queens are island mated. To get the best match of genes for each specific line we always use at least 2 different islands for the mating of the queens. The island of Tunø, which is my own mating station, and the island Mandø are used for most matings.
Every year we are wintering approximately 150 new island mated queens. These queens are tested for two years. The queens are evaluated on a number of inherited characteristics, the primary ones being: low swarming tendency, temperament, behaviour on the comb and honey yield.
In addition to the primary evaluation in the 1st year of the queens, our breeder queens are tested for Nosema tolerance and Hygienic behaviour.
The Nosema- and the Hygienic tests are stop tests, which means that queens who are not free of Nosema, or doesn't show a hygienic behaviour higher than 95% in 48 hours, will not be used as mothers for island mated or production queens. Most of the queens used as queen mothers are shoving 95% hygienic behaviour in 24 hours.
Selection for Nosema tolerant bees has been going on for the last 25 years in Denmark. All queens with breeding potential are, in the spring of their second year of life, laboratory tested for Nosema. Only queens, who have been tested free of Nosema, are used for producing queens for sale.
Hygienic behaviour is the newest part of the breeding programme. In late May, just before the grafting season starts, all queens with breeding potential are tested for their ability to remove freeze-killed capped brood. This has proved to be a very effective way of selecting queens with a high resistance to Chalkbrood and Foulbrood. When queens are selected for tolerance in this way, the widespread problems with these diseases are largely eradicated.
After 2 years of testing, 7-10 queens, from 5-7 lines, are selected as mothers for the current year’s production of new queens for sale.
Each year we participate in a consumer test conducted by the Association of Danish Beekeepers (DBF), where my queens have consistently shown high and stable results.
Random mating takes place in three forested areas, where we have good control over the mix of drones, which is necessary for the random mating of excellent production queens.
We strive to produce excellent queens, which possesses the following favourable characteristics:
• Resistance to disease
• Low swarming tendency
• Good honey gathering ability
• Good temperament
• Calm behaviour on the comb
Temperament, Bahviour on the comb and Swarming are graded on a 1 to 5 scale, where 5 is top of the scale.
In practical life swarming has only 2 characters - 1 or 5. Queens, of stable material, who are making attempts to swarm, will be culled out by the end of their first season. Only new material, who is evaluated for being a part of the main stock, will get a little tolerance in relation to swarming.
In relation to swarm testing, we put great emphasize on that no frames (brood or honey), are removed from the broodnest during the productive time of the season. The bees have to show, that they are able to keep a firm and clean broodnest by themselves. This strategy has proven to be quite important in relation to swarm testing and testing for general order in the hive.
After a couple of generations, with zero tolerance to swarming, swarming problems will be more or less eradicated.
Honey yield, Nosema level and Hygienic behaviour are all reported in exact numbers.
Honey is weighed from each test colony, and recorded in a spreadsheet.
Nosema test is done with a laboratory analysis on old bees, who are gathered in the early spring. The result are presented in a report as number of spores per microscope view.
Hygienic behaviour is tested with newly capped freeze killed brood, who are introduced in the test colonies and subsequently checked after 24 hours. The result consists of two values: Fully removed and partially removed larvae. By testing this way we are able to find the queens with extremely high hygienic behaviour (full removal in 24 hours), which is especially important when selecting dronelines for the following year.
The combined number of fully removal and partially removed larvae gives a value who is equivalent with 48 hour testing. This level is considered sufficient for queens who will be mothers for random mated queens. The tested brood comb holds 200 cells.
Note about Freeze kill test:
It's important to keep in mind that results from different testing strategies can not be compared with each other. Testing with freeze killed brood gives a more conservative, but uniform, result compared to f.ex. pin testing (piercing). This means that the result from a freeze test might look poorer, than the result from a pin test, if the test is done over the same number of hours.
Our testing strategy, on hygienic behaviour, is devolped and described to its full extend by Marla Spivak, University of Minnesota, USA.
Links:
The danish grading scale (with our personal improvements): Grading scale
Report about hygienic behaviour: Spivak
Report about Nosema tolerance: Nosema