Nosema

[karen]

I thought I would put the nosema in a new subject.

What I had written in snowmageddons: "I have been testing bees for nosema for people with dead hives and hives they are worried about because on any fly day piles of dead bees are out the door. There is a lot of nosema around, most of the samples have been positive with a heavy burden. We are seeing more nosema than most winters. I wonder why? Is it the different weather we are having this winter? Or that more people have gone away from treating prophetically? I never treat unless I see a problem. For the bees I have been asked to check it is to late, they are either dead or the cluster is so small they will freeze on nights like we're in store for tonight. One beekeeper who has lost 2 of his 3 hives has brought the last hive into his cellar and is feeding it fumagillin with plans to bring it out on a few fly days. He is going to follow CC Miller's (Fifty Years Among the Bees) cellar wintering for the rest of the winter but I saw so many spores on the slide I checked for that hive I will be surprised if they pull through."

Allen wrote: "Fumagillin is preventive, more than curative. Moreover, bees badly afflicted with nosema will not take syrup. Apparently HBH improves uptake, though."

I recommended drenching the hive the beekeeper brought into his cellar. I did tell him in our first communications to add HBH to his syrup if feeding but not if drenching. The drenching instructions I gave: "For ​drenching​ you need to do it ​3 times, once a week​ for 3 weeks​. The goal is to deliver the same total dose to a colony in several shots to be consumed in a short period. The drench is done with light syrup.

​​The normal mixture​ for fumagilin​ is 1 gallon syrup to 1 rounded teaspoon of ​fumagilin. ​​
​I have never drenched but have read 1 cup syrup to 1.5 grams of fumagilin per application​, which comes to @ 1/3 of a teaspoon.​ The 1/3 teaspoon comes to 1 teaspoon over the three weeks so equals a normal dose (though it says rounded teaspoon so for this I would use a gram scale for my 1.5 grams and not a measuring spoon).

He had asked about giving 4.5 grams in one drench I wrote back: I think 4.5 grams in one dose may be too hot of a dose. Be sure to dissolve the fumagillin in a little bit of warm water before mixing it in the syrup, it will not dissolve in the syrup.

I also told him: I doubt they live with that type of infection and being a small cluster. The queen is probably infected too. They will probably dwindle because they will not be able to raise brood. The hypopharyngeal glands of infected nurse bees lose the ability to produce royal jelly and if the queen is infected the eggs are to.

So you all can add your two cents worth, I will pass along anything that someone has had luck with and will also let you know if these bees live or die. Remember our average temperature has been 10 to well below -0 F (-12 C to -21 C most days) we have 5 feet of snow on the ground. So what works where you live may have to be handled differently here.

[Allen Dick]

I am always puzzled by the many differing observations around nosema and its control methods and am quite convinced that we till do not really understand nosema and its relation to honey bees at all.

In Edmonton recently, what I gleaned from the presentations is that prophylactic treatment with fumagillin seems to work some or most of the time, but there seems to be some still unidentified influence that has a huge effect on whether nosema is a problem or not.

The history of hives and beginning nosema levels seem to have a bearing on how effective fumagillin treatment is.



http://www.honeybeeworld.com/diary/2015/incl/Slides.htm

Neonics seem to me to be increasingly suspect as one of the unknown influences and what I saw at the meeting takes me back to what was mentioned around as one mechanism of neonics control of termites when neonics were first introduced: they increased severity of natural fungal infections on the termites. The response was that this effect was limited to termites and not applicable to bees. I have no references, so it may be just lore or a faulty memory, but that info stuck in my mind.

One other thing: drenching with fumagillan did not seem to be nearly as effective as the recommended method, but the drench was not repeated as I recall.