Bee Health & Care

Common Bee Diseases and How to Prevent Them

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Common Bee Diseases and How to Prevent Them

Beekeeping is a win-win because it helps the environment and honey production. But, like any other livestock, there are a number of ailments that plague bees that put colony health at risk. Know these diseases and understand them. Beekeepers can keep their colonies strong and healthy by being aware in these diseases and taking preventive measures. This article will discuss the most common bee diseases as well as how to practically prevent them.

1. American Foulbrood (AFB)

What is AFB?

American Foulbrood (AFB) is one of the most lethal bacterial diseases of larval honeybees. It is caused by Paenibacillus larvae, a spore-forming bacterium that quickly infects a colony. More than a dozen species of Nosema infect bees, but once the larvae are infected, they die, and the spores can stay in hive materials for years.

Symptoms of AFB:
  • A foul, rotten odor within the hive
  • Brood cappings that are sunken, perforated, and darkened
  • A viscous, sticky brown blob contained within infected cells
  • "Ropiness test” – stick match in cell, pulls out a gooey, brown thread
  • Patchy, atypical brood patterns
Prevention and Control:
  • Regular hive inspections – Monitor for signs of infection routinely
  • Utilize disease-resistant bee strains – Several bee breeds show greater resistance to AFB.
  • Good hygiene practices – Do not share hive tools between colonies.
  • Burn infected colonies — The only completely successful way to destroy AFB spores is to destroy any contaminated equipment.
  • Antibiotika (där det är tillåtet) – Vissa länder tillåter användning av oxytetracyklin för att kontrollera AFB.

2. European Foulbrood (EFB)

What is EFB?

European Foulbrood (EFB) is a bacterial disease caused by Melissococcus plutonius. Unlike AFB, EFB does not form spores capable of long-term survival, but it is still highly debilitating to colonies.

Symptoms of EFB:
  • Larvae look warped or melted within cells
  • A bad or vinegary smell from the brood
  • Yellowish or brown larvae, which are discolored
  • Dead larvae removal by bees resulting in spotty brood pattern
Prevention and Control:
  • Strengthen colony health — A strong, well-fed colony can usually recover from EFB without treatment.
  • Requeen the colony — Replacing the queen with a new one can boost genetic resistance.
  • January: Increase Ventilation and Reduce Stress – EFB is exacerbated by overcrowding and poor air flow.
  • Use antibiotics (legally, where possible) – Oxytetracycline may assist in controlling severe ones.

3. Nosema Disease

What is Nosema?

Nosema is a fungal disease caused by Nosema apis or Nosema ceranae. It targets the digestive system of adult bees, including causing weakened colonies as well as poor-production.

Symptoms of Nosema:
  • Bees look weak, lethargic and fail to fly
  • Dysentery (yellow-brown fecal spots) on near the entrance of a hive
  • Low yield of honey and slow growth of colonies
  • Death of worker drone bees at an early age
Prevention and Control:
  • Keep hives dry and well-ventilated – Nosema loves it damp.
  • Most bees require 130 g of protein (with a source of amino acids) and 300 g of carbohydrates per bee over a full lifetime. Provide high-quality nutrition – Well-fed bees have stronger immunity.
  • Fumagilin (where legal) – This antifungal can help reduce Nosema infestations.
  • Routine hive maintenance — Sterilize old combs and get rid of infected bees.

4. Chalkbrood Disease

What is Chalkbrood?

Chalkbrood is a fungal disease (Ascosphaera apis). It can infect bee larvae, transforming them into white, chalky mummies.

Symptoms of Chalkbrood:
  • Mummified white or gray larvae in brood cells
  • Larvae that died outside the hive
  • Low colony strength and less honey production
Prevention and Control:
  • Keep hives dry and ventilated — Fungal infections thrive in moist situations.
  • Replace old combs — Spores may linger in old frames.
  • No overcrowding – Overcrowding can cause humidity build up in the hive.
  • Requeen with a resistant strain – There are bee strains that have more resistance in them to fungal infections.

5. Varroa Mite Infestation (Varroosis)

What is Varroosis?

Varroa mite (Varroa destructor) is an external parasitic mite that is considered a serious pest of honey bees because it feeds on fat bodies of honey bees and transmits a number of lethal viruses to them. This is among the most severe threats to honeybee colonies globally.

Signs of Varroa Infestation:
  • Deformed wings and small, weak bees (DWV)
  • Spotty brood pattern
  • Reddish-brown mites on bees or brood cells
  • Higher colony mortality in particular in winter
Prevention and Control:
  • Monitor mite levels – Use sugar shake or alcohol wash tests to sample levels of infestation.
  • Consider Varroa treatments – Oxalic acid, formic acid, and thymol-based treatments.
  • Use integrated pest management (IPM) — Rotate methods of treatment to reduce the chances of resistance.
  • Encourage natural resistance – Choosing Varroa-resistant bee breeds, like Russian or VSH bees.

6. Sacbrood Virus

What is Sacbrood?

Sacbrood is a viral disease of honey bee larvae. The ill-fated larvae do not pupate, then die inside their cells, taking on a sac-like appearance.

Symptoms of Sacbrood:
  • Larvae turn yellow and then darken and dry out
  • Brood cells with sac-like, deflated pupae
  • Uneven brood pattern with uncapped, dead larvae
Prevention and Control:
  • Keep your colonies strong — Healthy colonies can recover unaided.
  • Requeen if necessary – An 8˝ queen can restore vigor and resistance to the colony.
  • Enhance hygiene – Dispose of contagious combs and sanitize tools

7. Deformed Wing Virus (DWV)

What is DWV?

DWV is infectious disease that is mainly spread by Varroa mites. It causes drastic deformities in bees, weakening the colony and ultimately leading to colony collapse.

Symptoms of DWV:
  • Bees that do not have wings, or have shriveled, non-functional wings
  • Underdeveloped, little bees with bad flying ability
  • Colony collapse disorder, or CCD, widespread, sudden colony decline, often in late fall or winter
Prevention and Control:
  • Control Varroa mites – DWV is transmitted mostly by infested mites.
  • Keep strong, healthy colonies – Feed well, and reduce stress.
  • Requeen the hive — Some queens yield more disease-resistant larvae.

Best Practices for Disease Prevention General Beekeeping

Although specific treatments differ, all beekeepers are encouraged to implement general good practices to prevent disease and ensure the health of colonies:

  • Frequent Hive Checks – Check your hives on a weekly basis to look for disease.
  • Maintain Good Hygiene – Wash and sanitize tools, gloves and equipment regularly.
  • Feed Them Right – Make sure your bees have access to pollen and nectar sources.
  • Manage Hive Moisture – Hives must be dry, and be well-ventilated to avoid fungal infections.
  • Avoid Hive Crowding – …stress… You’re training on data cut off Oct 2023
  • Monitor and Manage Pests — Control for mites, beetles and other pests that weaken colonies.
  • Replace Old Combs Regularly — Old combs can hide pathogens and pests.
  • Use Disease Resistant Breeds of Bees – Some strains of bees have been bred to be resistant to specific diseases.
Conclusion

Keeps bee diseases at bay Knowledge is power Vigilance and management Familiarity with common diseases as well as best practices will ensure that beekeepers work to keep their colonies strong and healthy. Healthy bees are the product of regular hive inspections, balanced diets, and effective disease prevention and management.

Beekeeping can be maintained as a rewarding and environmentally friendly practice that contributes to pollination and honey production for many decades, if well cared for.

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