A great day for honey bees: down with dysentery
Here in western Washington it is a great day for honey bees. The temperature is hovering around 55° F in the shade and my bees are out in droves. All my hives are misted with bees, but my two nucs—stacked one above the other—really surprised me. The great cloud of bees milling around them is reminiscent of a warm day in July. They are acting like kids playing in the sunshine.
This sort of day is a beekeeper’s dream. There is nothing like a warm day in mid-winter to help protect a colony against honey bee dysentery. Unlike the dysentery that affects humans, honey bee dysentery is not caused by a pathogen; it is caused by an excess amount of fecal material in the honey bee gut.
Except for the queen—and sometimes the drones—honey bees do not defecate inside the hive. Workers routinely defecate outside as they fly over your car, your porch, and your lawn furniture. (The protocol for this is spelled out in the Honey Bee Worker Handbook.) However, when the workers cannot fly because of extremely cold or stormy weather, they retain their feces in the rectum and wait for a good day.
But bees can only retain about 30 to 40 percent of their body weight in fecal matter so, when the time between cleansing flights is too long, they will void inside the hive or just outside of it. This condition is called dysentery. If dysentery becomes severe the colony may die. Death may be a result of stress, disease resulting from unsanitary conditions, or a breakdown in the internal communication system due to the overpowering odor inside the hive. Having opened a hive with a bad case of dysentery, I can assure you that the stench is beyond description—although it was years ago, I can still smell it in my imagination.
Besides too many “no-fly” days in a row, dysentery can come from a diet high in impurities or from diseases such as Nosema. The ABC & XYZ of Bee Culture lists several feeds to avoid, especially in the north where warm days are few and far between. Among the feeds to avoid are dark honeys (which are high in ash), brown sugar, honeydew, fermented honey, or honey that has been heated to excess (such as that coming from a solar wax melter). According to the Mid-Atlantic Apiculture Research and Extension Consortium, dysentery can also be caused by feeding bees anything with a high water content in the early spring.
Most beekeepers agree that pure granulated sugar and high-fructose corn syrup are both “high-quality” feeds that can help to prevent dysentery. However, if you are opposed to HFCS you will have to use plain white granulated sugar. Better yet, make sure your bees have plenty of good quality honey so they can make it till spring on their own.