Not all bees are created equal
Honey bees that have the recessive genes for uncapping and removal behaviour have been shown to be capable of dealing with large numbers of AFB spores in their colonies without showing visual signs of AFB. The gene frequency of these characteristics in the general honey bee population is about 20%. However, by controlled selection, this frequency can be increased substantially.
Selection of breeder queens producing worker bees that show uncapping and removal traits is the most practical means of increasing the level of hygienic behaviour in hives. A beekeeper can concentrate on rearing just queens from these breeders, although the increase in gene frequency would be quicker if both queen and drone selection was used.
The test for hygienic behaviour is simple and straightforward, and does not interfere with the normal queen rearing process. It should therefore be a part of every beekeeping outfit’s queen rearing programme.
How to test
To carry out the test, select a comb of freshly capped brood in the hive containing the breeder queen. The brood must be in the prepupal stage, just after it has been capped. Take a long, thin pin (such as an insect mounting pin or a small needle) and push it through the capping to kill the prepupa. Be careful not to disrupt the face of the capping any more than is necessary to insert and then remove the pin.
Continue putting the needle through enough adjacent cappings so that a circular pattern is created (about eight cells). Mark the frame with a pen or thumb tack and put it back in the hive.
Three days later, remove the frame. If the bees have hygienic behaviour, the circular pattern should be obvious, since the bees will have uncapped and removed the killed brood.
Carry out the test several more times to see if the hive produces consistent results. If it does, the queen heading the hive will have passed the hygienic behaviour test and can be considered as a potential breeder for queen production.