Nothing like nature to put you back in your place.
We were feeling pretty proud of ourselves after bottling 150 jars of honey in our first year of beekeeping on the Chronicle rooftop.
Then, as we approached our two hives on a routine check in late October – we saw carnage. Dead bees were scattered in a wide circle around the entrance to both hives.
We knew to expect some die-off with the approach of winter when the colony kicks out the male drones to conserve resources. but on closer inspection we saw that the wings of these bees were wrinkled and deformed, like flimsy plastic wrap.
We called Robert MacKimmie of City Bees, a local beekeeper who keeps data on his iPhone about bee diseases.
“Sounds like deformed-wing virus,” he said.
The ubiquitous varroa mite, a pinhead-size red crab-like creature with legs on one side of its body that works like a tick, attaching itself to the bee to suck blood and pass many types of deadly viruses.
Varroa mites are visible to the naked eye. For a human, it would be equivalent to having a grapefruit-size tumor on your body.
Every hive has mites, and beekeepers have various strategies for keeping them in check. but once the mite population overtakes the bee population, the hive can crash.
We knew this and had been taking measures. Because mites prefer drone larvae, we had been putting one shallow super frame in each deep frame box to encourage the colony to build drone comb on the underside of the small frame. once they built it and filled it with larvae, it became a decoy to attract the mites; we then scraped it off and gave it to Home & Garden Editor Deb Wandell’s chickens.
But apparently it wasn’t enough.
MacKimmie came by to show us how to do a “sugar roll,” to see how infested our hives were.
He scooped half a cup of bees (about 300 bees) into a large mason jar with a mesh lid. he poured in 2 tablespoons of powdered sugar and shook the jar vigorously for two minutes.
Then he turned the jar over and dumped the sugar onto a plate of water. the powdered sugar causes the varroa mites, which have suckers on their feet, to slip off the bees. they fell with the sugar into the water, and as the sugar dissolved, they remained floating. by counting them, we’d get an idea of the percentage of infestation.
MacKimmie’s mite chart says one to three mites per 300 bees is manageable. three to nine mites means the colony is headed for trouble, and above that the hive will probably die.
We returned the snowy, dazed bees to their hives, then went back and counted the mites on the plate: 18.
A low moment
It was one of the lowest moments in our year with the bees. we had to make a choice: do nothing and see how many survive the winter; if they perish, start over with a new queen and colony. or we could use a treatment that meant introducing chemicals into the hive but could save the bees.
We consulted with a half dozen beekeepers and decided to use Mite-Away formic acid strips. they are gel pads super-concentrated with the same formic acid in bee venom. It appeared to be the least-toxic choice. It smelled awful, and we wore protective gear to put one pad in each hive, laying it across the frames of the bottom box.
It was a tough decision, because over the long run, studies have shown that treating mites artificially only makes them grow into a stronger race of super-mite as they adapt to the treatments. For this reason some beekeepers advocate letting the mites and bees coexist and work it out. the varroa mite was originally a pest of the Eastern (Oriental) honeybee, and the two have since learned to live symbiotically. but our western Apis mellifera bees have not, and are still under attack.
Two weeks passed and the acid evaporated from the strips. whereas before we saw hundreds of bees with deformed wings, this time we saw only a few.
Still, some mites remained, and we decided to go with my grandfather’s method. we took a colander and shook powdered sugar directly into the hive to get the remaining mites to fall off.
A dozen fell off immediately, and we’ll keep sugar-dusting throughout the winter.
Of the encyclopedia of possible bee diseases and pests – American foulbrood, chalkbrood, nosema, tracheal mites, amoebas; or other invaders: birds, mice, rats, wasps and robber bees – we have the most common, and prevalent, one.
Staying on top of it is a year-round job. and it’s a good thing to know if you are considering becoming a beekeeper.
Like a fellow beekeeper once joked to me, “Beekeeping isn’t warm and fuzzy – but nobody tells you that. really, it’s entomology and pest management.”
Varroa mites (Varroa destructor), right, are pinhead-size, crab-like parasites that transmit diseases as they suck on bees’ blood. they weaken and eventually destroy a colony.
This article appeared on page N – 1 of the San Francisco Chronicle