Genetics to the Rescue...

http://en.wikipedia.org/wiki/Varroa_destructor
Varroa destructor

In the bee keeping industry there is a problem with a mite called Varroa destructor. As the name implies this mite does some real damage to honey bee colonies. The mite feeds on the haemolymph (blood) of adult and larvae stages of the honey bee. By feeding on the bee it causes many effects. These effects include introduction of viruses, decreased body weight, reduction of life, deformed wings and many more. Colonies that become infested with Varroa usually die within six months to two years unless steps are taken to reduce the infestations.  Chemical treatments can be used to reduce infestations, but it is not a sustainable way to limit the population in years to come do to the mite's ability to become resistant. Because of this fact people are looking towards breeding for hygienic behavior in bees.

At this moment research is being conducted to help the bees become tolerant to Varroa. The plan is to selectively breed the honey bees to increase their hygienic behavior.  Dr. Hunt and his colleagues did a study to try and find the gene that underpins increased mite-grooming behavior. Their objectives were to genotype individuals DNA and then locate candidate genes by using quantitative trait loci (QTL) mapping.  Individuals were chosen from their performance in a behavioral study. In the assay, a single Varroa mite was placed on the thorax of a honey bee that was inside an observation area. Two individuals then observed and timed how long it took the bee to respond by using grooming behavior. Grooming behavior in this assay was defined as “swiping motions in the direction of the mite with the front two pairs of legs.” Each colony that was tested had a phenotype estimated by the average reaction time of 40 workers.

http://beelebanon.wordpress.com/2011/05/11/
colony-collapse-disorder-and-resistant-pests-create-demand-for-new-treatments/

From the many colonies that were tested only two were choose to be backcrossed to create the population of bees that would be genotyped. The backcross breeding method takes the F1 (hybrid) individual (the queen) and crosses her back to one of the parental lines. The new populations of backcrossed workers were then tested on the same behavioral assay as above. From the recorded data, the top and bottom 98 bees for reaction time were chosen. The results from this study show that they were able to locate 27 candidate genes, but not able to find the specific gene that has the major impact on grooming behavior.

Can you imagine what this will mean if the gene is located?
By finding this gene it will make breeding so much easier. You wouldn’t have to go through the trouble of picking queens only based on observations of their workers productively against these mites. You would be able to genotype their DNA and figure out if the queen carries the right gene for the trait. Once this gene is found it will be a step in the right direction to make honey bees tolerant to the dreaded Varroa destructor.

Although this finding will help, more needs to be done to make the honey bee tolerant, one thing isn't enough to cause the change!

           

If you would like to read the paper:

 http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0047269

           

References:     

 Goodwin, Mark, and Eaton Cliff Van. Control of Varroa: A Guide for New Zealand Beekeepers. Wellington, N.Z.: New Zealand Ministry of Agriculture and Forestry, 2001. Print.