Joshua T. Summers, jtsummer@ncsu.edu, Jennifer J. Keller, jjkeller@ncsu.edu, Jeffrey Lee, and David R. Tarpy, david_tarpy@ncsu.edu. North Carolina State University, Department of Entomology, Campus Box 7613, Raleigh, NC
There has been a recent shortage of honey bees for pollination services within North Carolina, largely due to the parasitic mite Varroa destructor. A new mite-tolerant strain is available through the USDA, and the purpose of this study was to compare it to standard commercial stock and determine if it is a viable option for beekeepers across the state. We established six research sites across the entire state of North Carolina, two each in the Mountain, Piedmont, and Costal Plain regions. Each region had two bee yards containing either a standard commercial stock (‘Italian’) or the new mite-resistant stock (‘Russian’) for an initial study-wide total of 90 colonies. Varroa and tracheal mite samplings began in June 2004 and continued monthly through November. We did not detect any tracheal mite infestations in any of the worker samples, indicating that these parasites had not infested any of our experimental colonies. In contrast, there were significant differences in varroa mite levels within and among geographic locations. We detected significant differences in mite intensity among the three regions for all sampling periods (p<0.01), and we detected significant differences between the two stocks by the final sampling period (p<0.05). We also detected significant differences in mite prevalence between the two stocks by the fifth sampling period (p<0.05), demonstrating that the Russian colonies indeed had lower percent infestations (5.4%) than Italian colonies (8.3%). There were also significant differences between the two stocks in their survival over the course of the experiment. These data suggest that the new mite-tolerant stock is efficacious across North Carolina.
Species 1: Hymenoptera Apidae
Apis mellifera (Honey bee)
Keywords: Varroa mites, Disease resistance