Variable efficacy of mite treatments has been a constant battle for beekeepers in the past 28 years. However, there are some things we can do in the colony to increase a treatment’s efficacy. Many treatments available to beekeepers are spread through the hive by the bees and also by the bees fanning and ventilating the hive. This ventilation is a crucial part of the hive as a whole since pheromones are spread through the hive via ventilation and traffic from worker, queen and drone bees.
Through my experience, and especially over the past 8 years, I have noticed many different types of beekeepers: there are those who are diligent in scraping burr comb, there are beekeepers that scrape the hives only a few times a year, and those who choose not to scrape at all. After seeing this trend year after year the thought came to me, how does bur comb effect mite treatment efficacy? This question is still not answered scientifically but I do feel that contributes to the inconsistencies within apiaries treated in the same way. These varied results are especially noticed with using fumigation type treatments, one example would be formic acid or Mite Away Quick Strips (MAQS). There have not been any studies that I found on evaluating the treatments with or without burr comb but I think this something that needs to be and could be evaluated.
Scraping burr comb down 3-5 days prior to treatments could affect the efficacy of the treatment. I would not recommend scraping bur comb and treating within the same day due to hive stress from having to clean, repair and reconstruct ventilation pathways. During time of treatment, it may also be beneficial to feed the colonies some protein supplement, this will give the bees some extra food to cope with stress and also draw them closer to the treatment. Feeding sugar syrup is another method you can use to give the bees some help with coping with the treatment stress, but a fondant patty may be better because it will draw bees towards the treatment.
I have been scraping my hives since I started beekeeping because that was the way I learned, but only after many years have I realized that this habit may contribute to successful overwintering and more consistent mite treatments. I hope this information was useful and I would appreciate any stories or information on how scraping burr comb has increased or decreased efficacy of mite treatments.