Nosema is a common ailment in the spring, when the temps can get warm in the day but quite cold in the night time. This essentially gives bees a cold. Nosema is both the condition and the organism that causes it. In the U.S. there are two types, Nosema Apis and Nosema Ceranae.
Nosema is a fungus that lives in the bees gut and reproduces causing spores in the cell walls, then passing through the bees in their bee waste thereby spreading to other bees. Nosema is most prevalent in winter and early spring and is most obvious when the front of your hive is covered with lots of little specs (bee poo). In a nut shell, bees have dysentery and will expel their waste before the come into the hive all over the front. For new beekeepers, this only occurs on the front of the hive; don't confuse their waste with Propolus that is found under the lid when opening the hive.
Most cases can be treated with an antibiotic called Fumagilin-B with good success. Some hives can overcome this problem on their own, but you must keep a careful eye on them if you choose to wait it out, Nosema can cause rapid colony losses.
Of course there is a growing number of beekeepers that will debate the use of any kind of antibiotic in their hives or treatments in general. If we can only sustain our bees on antibiotics and treatments, then the bees we have may not be worth propagating. Shouldn't we breed only those bees which can survive on their own without our intervention in order to perpetuate a stronger strain of resistant bees? That is the question at hand and many have input from both sides.
For natural preventative treatments, we feed Tea Tree Oil in our sugar water in the spring. This natural substance helps jump start their immunity and has prevented us from having to use any antibiotics on our hives. Can we prove Tea Tree oil has worked? No, but we use it every spring, without fail and we don't have Nosema, so will we stop? No.
As usual, if you have any other questions about Nosema or other bee related question's, feel free to e-mail or call us. We are always here to help, no matter where you live.