Authors : Berna Emsen, Tatiana Petukhova and Ernesto Guzman-Novoa
Abstract: The objective of this study was to compare the hygienic behavior of worker bees (Apis mellifera) as well as infestation and reproduction parameters of the parasitic mite Varroa destructor between groups of honey bee colonies with high and low rates of Varroa population growth. More than 150 colonies were screened for mite fall in early spring and again 16 weeks later. The 10 colonies with the Lowest rates (L) and the 10 colonies with the Highest rates (H) of mite population growth were selected. These 20 colonies were evaluated for hygienic behavior, brood and adult bee infestation rates and mite reproduction in cells. The amount of brood and the adult bee population of the selected colonies were also estimated. No differences were found between the two groups of colonies for brood or adult bee population or for hygienic behavior. However, significant differences were detected for mite infestation levels and for mite reproduction. Brood and adult bee infestation rates in the colonies of the H group were 17 and 6 times higher, respectively than in the colonies of the L group. The proportion of reproductive mites was 0.92±0.05 in the H colonies vs. only 0.40±0.16 in the L colonies. Additionally, two times more immature mites were found in singly Varroa-infested cells of H colonies than in similarly infested cells of L colonies. Furthermore, the ratio of brood to adult bee infestation rate was 2.4 times greater for the H colonies in comparison with that of the L colonies. These results indicate that brood-associated effects may influence the growth of varroa mite populations in honey bee colonies. The implications of these results are discussed.
Berna Emsen, Tatiana Petukhova and Ernesto Guzman-Novoa, 2012. Factors Limiting the Growth of Varroa destructor Populations in Selected Honey Bee (Apis mellifera L.) Colonies. Journal of Animal and Veterinary Advances, 11: 4519-4525.