Use experimental colonies which have enough brood combs (i.e. more than six combs) in the hive. Take out a single comb containing newly capped brood.
With a color marker pen, mark the position of a cell or several cells just above three groups of nine newly sealed cells (Fig. 1). Mark also the top bar of the comb frame that contains the cells used for observation (Fig. 2).
Kill the larvae in a total of 27 cells of the comb by pricking them with a fine pin or needle. To make sure the larvae are killed, prick them several times at different angles (Fig. 1).
Place the treated comb back into the brood rearing area of the hive from where the comb was taken (Fig. 3).
Twenty four hours later after the larvae were killed, count the number of cells which have been uncapped and completely cleaned out (Fig. 4 and Fig. 5). Colonies where more than 24 cells (90%) have been cleaned out are considered to have the hygienic trait.
From the colonies found to have good hygienic behavior, new superior queens can be collected to replace old queens in other hives. This will improve the disease resistance of the bee colonies.
When colonies have been selected for their better hygienic behavior, using this method, beekeepers can then use the queen cells of the selected colonies for swarming, or for replacing old queens. The easiest way to introduce the new queen is to cut out the sealed queen cell with a sharp knife, and place it into the comb of queenless hives.
If beekeepers wish to rear many queens from a colony showing good hygienic behavior, they can use artificial queen cells (Fig. 6). They should take a comb containing young larvae of worker bees, and construct queen cells by grafting. Larvae from 8 to 36 hours old are suitable for grafting. They may be the same length as the eggs, or up to 50% longer.
Using a grafting needle, young larvae can be transferred from a worker comb to artificial cell cups primed with royal jelly. As soon as a series of cells has been grafted, the cells should be immediately given to a cell-building colony that is strong and separated from any queen (Fig. 7). After each grafted cell has been sealed, it can be placed into any queenless hive.
Figure 1 Marking and Killing the Larvae in Newly Capped Brood Cells
Figure 2 Marking the Frame Where the Comb Is Being Tested
Figure 3 Placing the Test Comb in the Hive.
Figure 4 All Nine Brood Cells Have Been Cleaned up One Day after the Larvae Were Killed
Figure 5 Only Five Cells Are Cleaned, Two Cells Have Been Uncapped but Are Not Cleaned, While Dead Larvae Still Remain in Two Cells
Figure 6 Worker Bees Build up the Artificial Queen Cells
Figure 7 Adult Queen Bees Attended by Worker Bees <BR>
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