FYI for those of you which may be interested. Measures were used in order to reduce the loss of Queens as briefly described in the abstract below. I am leaning toward the removal of queens before the flash treatment in order to protect valued queens. Look closely at the percentage of Varroa that was wiped out (inside capped brood). Is this not very encouraging? I may in the future do an experiment as described while incorporation suggestions from Mr HP and others in the above post. What are your thoughts? Is this a waste of time and effort? Or does this look promising to you?
RESULTS OF 50% FORMIC ACID FUMIGATION OF HONEY BEE HIVES [APIS MELLIFERA LIGUSTICA (HYMENOPTERA: APIDAE)] TO CONTROL VARROA MITES (ACARI: VARROIDAE) IN BROOD COMBS IN FLORIDA, U.S.A.
123 James W. Amrine, Jr. , Robert C. Noel and David Webb
1. Division of Plant and Soil Science, West Virginia University, PO Box 6108, Morgantown, WV 26506, U.S.A. (e-mail: jamrine@wvu.edu); 2. 108 Blackiston Avenue, Cumberland, MD 21502, U.S.A. (e-mail: rcnoel@atalanticbb.net); 3. 901 Elkcam Blvd., Cocoa, FL 32927 (e-mail: webbshoney@msn.com).
ABSTRACT - We used the 50% formic acid fumigator to treat 51 honey bee colonies in Florida on April 2, August 16 and October 23, 2006 and January 2, 2007, to control varroa mites. Treatments consisted of 90 to 110 ml of 50% formic acid mixed with 15 ml of Honey-B-HealthyTM essential oil concentrate to prevent queen losses. The fumigator was applied during daylight hours to each hive, screened bottoms were cov- ered, openings taped over, and the entrance reduced to 3/8? by 3 1/2? (0.95 cm x 8.9 cm) and removed the next day after from 17 to 23.3 hours. Average mortality of varroa mites in capped drone cells was 93% (92.8% to 98.8%) (after adjustment for Abbott?s correction for control mortality). Capped drone cells in old black comb had the lowest mortalities (66% to 84%): less of the 50% formic acid vapor was able to pene- trate the thicker cappings.
Key words - Acari, Varroidae, varroa mites, formic acid fumigation, control, U.S.A.