Richard Campbell sprinkles powdered sugar on his honeybees to control parasitic varroa mites that attach themselves to backs of bees like small ticks and drink hemolymph, or bee blood. Campbell, director of horticulture at Fairchild Tropical Botanic Garden, long has had a hobby of beekeeping and oversees hives at the Fairchild Farm, at the Garden in Coral Gables and at his home in Homestead. The powdered sugar causes honeybees to groom themselves and scrape off the mites.
|Applying powdered sugar to honeybees.|
“This year, I had a big problem because I didn’t have enough drones and ended up with queens that only lasted six months,” Campbell says. “There was not enough sperm. My queens had varroa and I didn’t know it. I had one queen I really liked and collected (larval) cells from her, but they’d all been damaged by varroa and were rejected. When the larvae come out, the colony will force them out or kill them.”
Campbell’s bee woes, from fewer drones and queen longevity to mites, have been repeated everywhere across the country, with the result that the inner workings of beehives have never been more fully studied than they are today. Since 2006, beekeepers in North America and Europe have been losing bees at an average rate of 30 percent a year – making it harder and harder to produce enough healthy honeybees to pollinate such crops as almonds, cranberries, blueberries, carambolas, avocados, eggplants, rapeseed, watermelon and many others.
Dusting bees with powdered sugar is a remedy for varroa mites that most commercial beekeepers don’t have time to apply, but it is increasingly discussed online as beekeepers struggle to maintain their colonies. The mites, originally believed to be from Java but now found worldwide, have been found to depress the immune system of bees, making them more susceptible to diseases and pesticides and to spread viruses such as deformed wing virus and acute paralysis virus. To control varroa mites, which arrived in the United States in 1987 from Brazil, beekeepers initially relied on chemical miticides, which depress reproductive activity in the colonies.
Other diseases that may plague honeybees include nosema virus (which is actually a gut fungus that gives bees dysentery when they are confined to their hives in winter), bacterial diseases, hive beetles and wax moths. But more attention is being paid these days to a relatively new form of systemic pesticide that may be adding to the misery.