A fight with the varroa mite in New Zealand
Varroa destructor hit the North Island first. It established around Auckland and spread gradually south. At first, beekeepers negotiated quarantine lines. Some apiaries were split down the middle, and boundaries had to be renegotiated every time the infestation spread. And in the meantime, an infested feral colony rode a hollow log into Wellington and Frank’s bees became the first in the area with Varroa.
Frank did not shy from the “bad beekeeping” stigma that encourages beekeepers to under-report cases like this. Instead, he worked to contain the infestation. He marked a five-mile radius around the Varroa hive, determined to destroy neighboring colonies to prevent Varroa from spreading. Frank climbed fences, turned ankles, and plugged and poisoned the wild beehives inside his quarantine zone. He offered honey to people who could point him towards feral colonies. He even managed to poison a nearby beekeeper’s unregistered hives—by mistake, of course—he had thought they were abandoned.
Frank got most of the ferals. All but one colony, actually, because it was on private property and the owners would not grant him access. So Varroa proliferated in the Wellington area, expanding outwards as the northern population spread south. The quarantine was a losing battle, Frank says.
That’s part of what makes Frank’s effort so admirable. Facing an impossible task, he refused to give up. These days, in anticipation of miticide resistance, he is exploring alternative Varroa treatments. In order to monitor mite levels, Frank “fogs” his hives with vaporized food-grade mineral oil (FGMO) using a small flamethrower. He shows me how to pump a few puffs into the front entrance of each hive and warns me not to place the fogger too close. The popcorn sound is bees cooking, he says. Overall, casualties are relatively low. Frank estimates that we’re singeing the wings of approximately twenty bees per hive. After fogging the first apiary, I am red-faced and dizzy. Frank mentions that a dusk-mask would be advisable.
The fog agitates the mites, providing a one-day knock down, but it does not kill them. We collect the mite fall on slide-out “sticky boards” on the floor of each hive. These help us determine whether to implement a follow-up cord treatment. The short cotton cords are soaked in a solution of equal parts honey (or sugar syrup), food-grade mineral oil, and beeswax, adding 5% thymol for extra effect. Once dry, they are placed on top of the frames, two cords per brood box. The honey attracts the bees to the cords, and the FGMO kills the mites. Frank treats with cords about once a month, as needed.
These techniques were developed by Dr. Pedro Rodriguez of the United States, but Frank is experimenting with them himself to determine which treatments work best for his bees. It’s extra work for uncertain payoff. That’s some admirable beekeeping.