When we talk about the health of our bees, few things are more quietly destructive than Nosema.
If you’ve ever noticed your colony struggling and couldn’t quite put your finger on why — it might be Nosema working behind the scenes.
Let’s dive into what it is, how to spot it, and most importantly, how we can stay one step ahead.
What Exactly Is Nosema?
Nosema is a disease caused by two sneaky little parasites — Nosema apis and Nosema ceranae.
They’re tiny, spore-forming fungi that invade a bee’s digestive system, wearing down the colony’s strength over time.
It doesn’t always announce itself loudly. Sometimes, the only sign you’ll get is a colony that just isn’t bouncing back the way it should.
How to Spot Nosema in Your Hive
Nosema can be tricky because its symptoms often overlap with other issues. But knowing what to look for can give you a big advantage.
If it’s Nosema apis, you might notice:
- Yellow or brown streaks (dysentery) at the hive entrance — especially after a long winter.
- Worker bees that seem weaker and live shorter lives.
- A queen that’s not laying properly, or being replaced altogether.
- Nurse bees struggling to feed larvae properly.
- Bees crawling around outside the hive, unable to fly.
- A slow start to spring — the colony just isn’t building up.
- Less honey coming in.
- More dead bees and hive debris than usual.
- Higher losses over winter.
If it’s Nosema ceranae, it’s even sneakier:
- No obvious dysentery — entrances might look totally clean.
- Bees seem “fine” — but the colony is shrinking.
- Brood patterns are spotty, the queen slows down, or disappears.
- Sudden colony collapse, even in what seemed like a strong hive.
- It lingers year-round — not just over winter.
- Honey production drops without an obvious cause.
Sometimes, especially with Nosema ceranae, the only way to know for sure is to send a sample off for testing. If something feels “off” in your hive, trust that instinct.
How Does Nosema Spread?
It’s all too easy for Nosema to get into a hive. Bees pick up spores from contaminated food or water, and once inside, the spores germinate in the gut, multiply, and tear up the bee’s digestive cells.
Infected bees then spread the spores through their faeces, contaminating the hive surfaces, honey stores, and combs — meaning others get infected just from doing their normal jobs.
It’s a vicious cycle if you don’t catch it early.
How You Can Fight Back Against Nosema
While there is no guaranteed cure for Nosema, good beekeeping practices can significantly reduce its impact. Maintaining strong colonies is crucial.
Here’s what’s worked for us and countless other beekeepers:
- Leave enough honey on the hives in autumn. It’s better to lose a little honey than a whole colony.
- Feed strategically. Use pollen supplements like NuPro and sugar syrup, with 2.5ml of Hive Alive per litre during times of shortage.
- Boost their gut health. Probiotics like Strong Microbials SuperDFM can make a real difference.
- Rotate out old combs regularly to lower contamination.
- Requeen with strong genetics — queens that can handle stress and disease.
- Pack down for winter. Reduce the number of boxes and concentrate the bees’ heat and resources.
- Minimise winter stress. Avoid shifting hives once the cold sets in.
- Consider the shook swarm method to transfer bees into clean, fresh gear.
- Use irradiation on empty hive equipment if you can — it’ll wipe out Nosema and a lot of other pathogens too.
(By the way — if you’ve heard of fumagillin treatments, they’re pretty outdated now because of resistance issues and residue concerns.)
Why It Matters
When Nosema gets the upper hand, it doesn’t just hurt a single hive — it chips away at your whole apiary’s success.
Weak colonies are more vulnerable to pests, other diseases, and harsh weather.
Healthy bees, on the other hand, are the heart of everything we do.
Spotting the signs early, keeping nutrition high, and focusing on prevention means you give your bees the best chance not just to survive — but to thrive.
At the end of the day, beekeeping isn’t just about reacting to problems — it’s about caring enough to stay ahead of them.
Regular inspections, strong nutrition, good hygiene — these small, steady habits are what set thriving hives apart from struggling ones.
If you ever suspect Nosema in your colonies, don’t wait. Start supporting your bees straight away.
Our bees depend on us, just like we depend on them.
Let’s do everything we can to keep them strong.