Beginners Honeybee Diseases & Pests Part 1

Beginners Honeybee Diseases & Pests Part 1

There are many diseases & pests that can harm and endanger the health and survival all our honeybees. The severity of each of these diseases & pests varies considerably, as does the ease of how they are prevented or resolved. We will look at one of these threats to our honeybees, Nosema.

Nosema Apis

Nosema is one of the most common disease among adult honeybees. It is a spore forming parasitic fungus.

There are two types  Nosema Apis & Nosema Ceranae

Nosema Apis is the original Nosema we had to face. It attacks the cells lining the gut of the adult honeybee and is associated in main to our colder climate. This is because bees are more prone to Nosema Apis when they have limited opportunities to fly.

Nosema Apis causes dysentery and confined to the hive due to poor weather and winter clustering the bees will / can defecate in the hive. The spores from Nosema Apis are then spread rapidly by bees moving around the hive and when honey bees ingest the spores. This can happen when bees are cleaning the combs or other parts of the hive including frames.

The spores are highly resistant to extreme temperatures and dehydration. You cannot decontaminate comb by freezing the spores will survive extreme freezing
The easiest course of action is to use fresh new foundation and recycle the beeswax for other uses.


  • An inability for some bees to fly bees walking on the ground
  • Fesses on comb and frame tops
  • Fesses on front
  • Piles of dead bees inside and outside of hive
  • The slow or stunted build up the colony in the spring and early summer

Sometimes you may not even see any of the signs especially if there is only a slight infection in the hive. The only sure and reliable method to tell is through microscopy. This means you either have the skills and microscope necessary to identify Nosema local beekeeping club may be able to help Bees in a hive infected by Nosema Apis may live half or less of their expected lifespan and the colony as a whole produces less new brood and can completely dwindle and die. Since Nosema apis usually causes dysentery like symptoms such as distended abdomens and defecation in the hive, it can be confused with normal wintertime honey bee dysentery which also causes distended abdomens and defecation in the hive. That why proper identification of Nosema is needed.

Because infected workers bees usually do not attend to the queen, she is less likely to be infected and will not need replacing.


A strong well-nourished hive of bees especially going into winter. Feed when there is a dearth (shortage of flow) this will keep the bees from running low on stores and prevent any stress on the colony also make sure they have a nutritional variety by feeding pollen substitutes if needed.


Some parts of the world allow Fumagillin an antibiotic now banned in the UK to treat hives infected with Nosema. While it doesn’t actually kill the Nosema spores, it does prevent them from reproducing in the gut of the adult honey bee in the UK there is no real treatment for Nosema. A Thymol syrup can be used some have had reported successes but there is at present no licenced products for treatment.
Recycle wax and heat scorch inside of hive to destroy spores.
Maintain large colonies going into winter. Combine small colonies with larger ones as long as they are all healthy.

  • Keep hives in a sunny location during winter to encourage cleansing flights when temperatures allow.
  • Make sure that colonies have adequate supplies of both honey and pollen going into winter.
  • Treat for Varroa mites. Bees weakened by mites are more susceptible to every disease.
  • Replace old combs with new ones to prevent any disease build-up.

(Some new research is showing comb replacement is not as good as first thought to overall hive health but nothing firm as yet)

For a simple easy to follow guide to Nosema testing take a look at Scintific Beekeeping

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