AN EVALUATION OF COMMERCIALLY-PRODUCED QUEENS THAT HAVE THE SMR TRAIT

Authors: Harbo, John; Harris, Jeffrey

Submitted to: American Bee Journal
Publication Type: Popular Publication
Publication Acceptance Date: 2/2/2003
Publication Date: 3/1/2003
Citation: HARBO, J.R., HARRIS, J.W. AN EVALUATION OF COMMERCIALLY-PRODUCED QUEENS THAT HAVE THE SMR TRAIT. AMERICAN BEE JOURNAL. 2003. VOL. 143, pgs. 213-216, Edition #3.

Interpretive Summary: Varroa destructor, a parasitic mite of the honey bee, is the number one problem in the beekeeping industry worldwide. One solution to this problem is to breed honey bees for resistance to these mites. With selective breeding techniques, scientists at the Honey Bee Breeding and Genetics Laboratory in Baton Rouge, Louisiana, have developed a trait of the honey bee that prevents mites from reproducing. Colonies of bees with this trait (called suppression of mite reproduction or SMR) are genetically resistant to varroa. ARS is cooperating with Glenn Apiaries in Fallbrook, California, to deliver this mite-resistant trait to the beekeeping industry. The objectives are to provide beekeepers with immediate relief by providing mite-resistant queens and long-term relief by increasing the frequency of mite-resistant genes in our population of honey bees. To determine if the release of this trait is providing immediate benefits, Baton Rouge scientists evaluated free-mated SMR queens that were commercially available to beekeepers in 2002. Colonies with these queens are expected to have about 50% of the SMR trait. Those colonies ended the test period with about half as many mites as control colonies that contained unselected queens. This showed that colonies with as little as 50% of the SMR trait can provide a significant level of resistance to varroa mites.

Technical Abstract: This study demonstrated that commercially-produced queen bees, Apis mellifera L, could provide a high level of resistance to Varroa destructor when free-mated with unselected drones. The test compared the growth of mite populations in colonies of bees that each received one of the following queens: (1) resistant, queens selected for suppression of mite reproduction and artificially inseminated in Baton Rouge with drones from similarly selected stocks; (2) resistant ¿ control, resistant queens, as above, produced and free mated to unselected drones by one of six commercial queen producers; and (3) control, commercial queens chosen by the same 6 queen producers and free mated as above. All colonies started the test with about 1.1 kg of bees that were naturally infested with about 130 mites. At the end of the 137 d test period, the resistant colonies (n = 5) had 36 ± 13(mean +- SE) mites, resistant ¿ control (n = 11) had 1059 ± 360, and the controls (n = 13) had 2711 ±343. These results suggest that beekeepers can derive some immediate benefit from mite-resistant queens that are available from commercial queen producers.