Nosema - What Now?

I’m pretty sure my two hives are on the edge of death due to Nosema. Does anyone have any tips or advise? Should I clean the hives before starting again, or requeen and hope for the best?

Hi @JessicaCole,

May I ask, why are you pretty sure? The reason I am asking is that usually knowledge of nosema does not lead to the question below.

If it is nosema, a new queen will be infected too. Just cleaning the hive will not suffice. Good cleaning followed by good use of a blowtorch will help though.

Last winter/spring I thought a colony I had nosema but wasn’t sure. I had placed the hive near a large dam and thought it might be too much extra condensation for the hive, resulting in dysentery. I recall being advised when camping, not to put the tent too close to a river etc as it would lead to increased condensation inside the tent. I put a moisture quilt in the hive and the dysentery was soon gone. I have since moved the hive further from the dam and haven’t had an issue since. I’m not saying this is the situation in your case, but it might be a possibility depending on location.

Yes, ours is about 20m from a dam. I’ll look into the quilt idea - thanks for the tip!
Unfortunately I think they’re too far gone now - will inspect them on Sunday and go from there. Thanks again.

Hi @JessicaCole - thanks for reaching out to the forum.

I wonder if you believe your colony has nosema due to what they’ve been foraging on, combined with the wet weather (I believe watered down nectar can make bees sick/give them nosema).

I know of a super knowledgeable beekeeper in rural NSW too (Mendooran), Adrian Grew, The Bee Farmer (you may be familiar with him) that knows a lot about this topic and your bees may be foraging on the same trees. He’s actually a newly signed up Flow Ambasasdor. I recommend getting in touch with Adrian to ask for his advice. He also runs really quality beekeeping courses, beginner, intermediate and advanced, that I also recommend.

We’d love to know how you go!

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It happens quite often when a beekeeper sees bees with diarrhea, the first thought is nosematosis. But diarrhea may be caused by many other problems - bacterial infections, honeydew toxicosis, chemical poisoning and salts in winter stores to name a few.
It could be just diarrhea caused by food containing something bees cannot digest. Unrefined sugar, burned sugar syrup, fruit juices, confectionery, not fully inverted sugar in winter stores etc. Usually, it happens while wintering but may happen after a long spell of bad weather when bees cannot fly.

There are other signs of nosematosis that can be observed, but none of them is really specific to this disease. Lab work is needed to confirm. Spore count followed by spore viability test because just the presence of spores doesn’t tell much.

There is another problem with nosematosis. It often goes together with other bacterial and viral infections.

Given all the above, the advice range for “I think I’ve got nosema” could be from “stop feeding that brown sugar” to “burn your apiary down including the top 100mm of the soil” with anything in between. When it comes to diseases, please use professionals for advice.

Thanks for your reply. Great points.
We’ve had a massive reduction in colony numbers, hundreds of dead bees at the entrance which tremble before dying, absolutely no brood what so ever, and they’ve eaten all of their honey stores (over 45kg worth!) in a few weeks. There’s been some diarrhoea but thought it could have been because of all the wet weather they couldn’t leave the hive to do their business, but sounds like all symptoms link back to Nosema? I called DPI and lab in NSW and both seemed disinterested - I’ll call again today to state I’d like to send off samples before buying more colonies.
Thanks again for listing the other possibilities - we’re new to this, so that’s super helpful!


Super interesting and doesn’t sound good at all. Thank you for caring so much, and investigating!

Again, I highly recommend Adrian, and would love to know what you find out.

Thanks, I’ll get in touch with Adrian and let you know what he thinks!

Hi Jessica,
I didn’t realise how far gone they were until seeing your pic. Definitely worth following up to find the cause. Good luck!

An increase in food consumption is an interesting thing because at the first stage of the disease food consumption goes up. Mainly pollen but honey too. However, 45 kg in a few weeks? Are you sure that your hive hasn’t been robbed and the queen killed during the raid?

That was our initial thought, but the dead bees at the entrance made us think it was something else…?
Yeah, they consumed the full super and all honey cells from the brood box, quite quickly. Definitely not normal. And this was evident in both of our hives.
Thanks so much for your replies! It’s good to bounce ideas.

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Anyway, it is all academic at the moment until and if DPI will do the test.

The real question is what to do now. Let’s assume not horrible, but just a bad variant :slightly_smiling_face:

Definitely no requeening because most likely it will be just a waste of time and money.
Don’t bring new colonies yet for the same reason.
Destroy remaining bees. Collect rubbish from the ground with dead bees under the hive and within a couple of metres around and burn it.

Do you know how and are you capable to disinfect your hives? Traditional disinfectants used in beekeeping are 2% hot solution of sodium hydroxide or 5% sodium carbonate. Both are corrosive, so knowledge of the basics of chemical safety is needed. If not, you may go with a heat gun or blowtorch (doesn’t work with flow frames though :frowning_face:).

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