ABRC2010 A New Assay to Measure Mite Grooming Behavior

The following was presented at the 2010 American Bee Research Conference in Orlando, FL.

3. Andinof, G.K. & G.J. Hunt – A NEW ASSAY TO MEASURE MITE GROOMING BEHAVIOR – Grooming behavior is one of the known mechanisms of defense for honey bees against parasitic mites. Varroa destructor is often considered the biggest beekeeping problem within the U.S. and around the world. Mite-grooming behavior has been described as the ability of the adult bees to remove Varroa mites during grooming and has been associated with mites that have been chewed by the bees’ mandibles, but the proportion of chewed mites is extremely tedious to measure.


Figure. Relationship between the % of mites removed and the % chewed

We developed an easier assay to measure mite-grooming behavior that can be used for selection in breeding programs. Wood cages with screened tops and bottoms were used to hold a frame of bees collected from the brood nest. Bees were transferred to comb containing pollen and nectar but without brood. The mites removed during grooming were collected in sticky boards for three days at room temperature (22-25 °C) and then counted. The remaining mites on the adult bees were collected and counted using carbon dioxide (CO2) to anesthetize the bees and powdered sugar to remove the mites. The percentage of the mites removed was calculated.

A significant relationship (p = 0.0285) was found between the proportion of mites removed in the lab assay and the proportion of chewed mites on sticky boards from the source colonies. This relationship indicates that the colonies that removed the highest percentage of mites in the caged adult bees were also the colonies that had the highest percentage of chewed mites (Figure). These results suggest that the method used to measure mite-grooming behavior is effective. In addition, we also found a negative relationship (p = 0.0072) between the percentage of mites removed and mite infestation of adult bees, which indicates that the colonies with the highest percentage of mites removed in the cage assay, had the lowest population of mites on adult bees. These results suggest that the low population of mites present on the adult bees is due to grooming.

More presentations from this conference can be found at Proceedings of the American Bee Research Conference 2010