I decided to try a prophylactic mite treatment for my hive after doing the powdered sugar roll a couple weeks ago. You may recall that my test failed due to operator error and it appeared that I did not have any mites. However, among beekeepers in this part of southern California it is known that no mites is highly unlikely, so I was fairly certain that I have mites in my colony; I had simply failed to detect them. I spoke with my beekeeper friend who shared with me some pictures of mites on the bottom boards of her colonies. We even played a little “Where’s Waldo”-esque game of Find the Mite to help me develop a good search image. Equipped with this information, I carefully searched the bottom board a few days later and I found a couple of the little buggers. (Side note: my aging eyes are getting more problematic. I’ve found that even wearing my glasses, the mites are too small for me to be certain of them so now I take a picture of the area where there is something that resembles a mite and then zoom the picture in closer to confirm. Perhaps I’ve found a use after all for Marc’s odd real estate gift magnifying glass he handed me a few weeks ago.)

European honeybees (Apis mellifera) are not co-evolved with the Varroa mite so they have not developed adequate adaptations to this threat, which they have only been dealing with since sometime in the 1960s for the species, and since the 1980s in North America. Varroa mites were originally known in Asia where they parasitize Asian honeybees (Apis cerana), a different, albeit sister, species. I’ve been looking into the array of methods one can use to treat for these mites and the reasons for and against treatment. As a biologist, I tend to agree with some of the treatment-free beekeepers I’ve read. In this philosophy, mite infestations are generally viewed as a genetic issue best handled by re-queening from a treatment-free breeder. A queen bred from stock that has survived without the use of chemical treatments should have genes better adapted to combating and co-existing with the mite. This is why I opted to purchase my queen where I did, since they have queens that have been selected for what is known as VSH, Varroa selective hygiene. Increased mite resistance is also one of the advantages for keeping feral colonies with some Africanized genetics who seem better-adapted to handling Varroa.

A powdered sugar dusting is one non-chemical method that can be used to encourage bees to clean themselves, which results in mite removal. This method does nothing for the mites that are busily reproducing in the capped brood cells, so multiple treatments are needed in quick succession to have any hope at reducing mite numbers. On some sites I’ve read that store-bought powdered sugar, which contains corn starch, is hazardous for bees and it’s recommended to make your own by putting granulated sugar into a blender. Other sites have cited research that cornstarch-laced powdered sugar is not harmful to bees, but other anti-caking agents are. I had powdered sugar on hand, so that’s what I used. After checking the bottom board this morning, I counted five mites. I’ll check the board again the next two days so I can get an average daily mite drop, and I’ll sugar them again in a week. Aside from the mites, the colony appears healthy. They are chugging through their sugar syrup and there were plenty of bees, capped brood, and capped honey visible on the few frames I pulled out.