What Bugs the Bees
Created on 11/18/2009
For the past three years there’s been an increasing concern about the health of our nation’s - and actually the world’s - honeybee population due to a mysterious malady referred to as Colony Collapse Disorder (CCD). What’s particularly puzzling about this condition is the bees seem fine one day, and they’re gone the next. No warning signs, no indication of disease, and the honey remains. What’s even more shocking is hives are typically not raided by mice, wasps or other scavengers, which would be the normal course of action if healthy bees swarmed from a hive. Although CCD doesn’t appear to be as much of an issue in 2009, scientists still don’t quite know what’s happening.
I’ve heard some pretty wild guesses on what’s causing CCD ranging from cell phone towers to pesticides. Thankfully, here in Montana we have one of the world’s leading bee researchers, Professor Jerry Bromenshenk, at Montana State University who is leading the charge with his students to figure out what’s causing CCD.
At the moment, their best guess is a fungus called Nosema ceranea, although they think it might be a combination of this strain of Nosema, as well as pesticide use and possibly Varrao mite infestations. So, instead of finding the magic bullet to fix everything, it may be a matter of improving the health of the hives to keep them strong enough to resist these factors.
Fungus and mites are nothing new to beekeepers. We deal with Nosema apis on a regular basis. It causes diarrhea in bees, which is obviously from streaks of yellow/orange feces all over the outside of the hive or on nearby structures. Just like anyone with a bad case of the runs, the bees are weak and cannot do what they need to on a daily basis. The best way to prevent it is to keep plenty of ventilation in the hive – even in the winter we crack open the top on warm days to allow fresh air inside. We also treat the colonies with Fumidil, an antibiotic specifically used in beekeeping, in the early spring (before nectar flow) and the fall. We mix it with powdered sugar and sprinkle it over the frames inside the hive. Other beekeepers sometimes mix it in sugar syrup, and feed it to the hive in the spring and fall.
The other constant concern in beekeeping is mites. Tracheal mites live and breed in the trachea of young bees, which weakens and eventually kills the individual bee. If left unchecked, it picks off an entire hive one by one. And when you’re looking at a hive with 50,000 members, that’s a lot of bees! Menthol in various forms is the best way to treat tracheal mites, although it’s tricky because it’s so temperature sensitive. If it’s too cool, the fumes don’t penetrate the entire hive. Too hot and it melts. Tracheal mites are also tough because you can’t see them unless you dissect the bee. If you have a significant die off in your hive, it might be worthwhile to take samples to a lab at the Department of Agriculture in your state, or your local extension office to see if they can locate mites in the bees.
Varroa mites are also fairly common, but they are visible with careful inspection. If you have a lot of dead bees on the bottom board, shake them on a light board and see if you can see tiny (we’re talking the size of a pin head) oval, brownish mites. Varroa mites attach themselves to the bees at the thorax, pierce their exoskeleton and consume the hemolymph (blood). Obviously having these little vampires clinging to them greatly weakens the bees, and a heavy infestation of varroa mites can wipe out a colony. They’re treated with Apistan strips (fluvalinate) that are hung vertically in the hive when varroa mites are confirmed before and after honey flow.
Honeybees are like any other type of livestock. They have pests that prey on them just like cows or hogs. But the difference with bees is a third of everything we eat depends on them doing what they do best – pollinating our farms, gardens and orchards – so it’s a good idea to keep them healthy!
