Lack of fall honeyflow could increase mite-induced honeybee deaths, again

Bangor Daily News

By Peter Cowin, Special to the BDN

Another dry summer in the Hampden area and again my bees are suffering from the failure of the fall goldenrod honey flow.

While I will be frustrated at having a smaller honey harvest than I had hoped for, I will be worried about what this means for the survival of our honeybees over the winter. We seem to be having a rerun of last summer where dry conditions resulted in the fall flowers, dominated by goldenrod, producing little nectar. The plants bloom like they always do but they can not make the nectar in sufficient quantity which our bees need to fill up the hives for winter. The bees are accumulating some stored honey but not the fall bounty we have had in previous years. There is still time for the honey flow to improve as other plants like bamboo and asters start to bloom and I am not too worried that the hives will have enough food to survive the coming cold months. My bigger concern is the more subtle consequences of a poor fall honeyflow.

In a more typical Fall, the hives are accumulating a lot of honey, perhaps 20 to 30 pounds per week in a fair year, 50 to 60 pounds per week in a bumper year. A colony bringing in lots of food is healthy and happy. We really want our bees to be really healthy in the fall as they prepare for winter so mite-borne viruses can’t get a foothold in the population. The lack of a honey flow stresses bees, stress makes the bees more vulnerable to viruses which ultimately kills the bees over the winter. That means, after a poor fall honey flow, a lower number of mites in the hive could give the colony problems compared to a year with a good honey flow in the fall.

Mites and the viruses they bring into the hive are directly responsible for more colony deaths than all other factors combined. It is important to control mite levels even when the honey flows are good. But when they are bad it is essential that mite levels are held even lower. I control mites in my hives by the application of a variety of organic mite treatments which kill most of the mites in the hive but don’t harm the bees if used properly. The population of mites will start to bounce back up as surviving mites reproduce and field bees rob honey from colonies that had not been treated and are starting to collapse. Mites in dying hives climb aboard robber bees and get a ride to their hive. So to keep mites under control hives often need treating again, perhaps several times in the season. In most years with average weather and average mite loads, treating the hives once in July/August and once September/October would be sufficient to insure low enough mite levels that few died from that cause. Last year I demonstrated to myself the huge benefit of mite control on winter survival. In two of my bee yards I treated the hives once for mites in late summer, all of these hives died. In two of the yards I treated hives for mites in late summer and late fall, these hives had about 50 percent survival. The last, larger yard I treated for mites late summer, early fall and late fall, and had 80 percent survival.

Lesson learned, this year I treated for mites in mid July and mid August and plan to treat all hives again in late September and early November. Given the poor honey flow now I am very glad that I opted for this regimen. I urge any beekeeper who has not yet treated their bees for mites to treat right away and at least one more time this fall, preferably twice more. Mite treatments cost a lot less than new bees!

For those interested in learning more, I have beekeeping classes coming up in the region from September through December. Check “The Bee Whisperer” Facebook Page for details.

Peter Cowin, aka The Bee Whisperer, is President of the Penobscot County Beekeepers Association. His activities include honey production, pollination services, beekeeping lessons, sales of bees and bee equipment and the removal of feral bee hives from homes and other structures. Check out “The Bee Whisperer” on Facebook, petercowin@tds.net or 299-6948.