Affected hosts
- Apis mellifera
Infection by Nosema apis
Nosemosis by Nosema apis
Intestinal infection of adult bees by a microsporidian, traditionally associated with dysentery, reduced longevity, and poorer colony performance.
Agent
Nosema apis
Legal status
Yes
Signs and symptoms
Adults
- Bees with a distended abdomen
- Inability to fly in severe cases
- Reduced longevity
Colony
- Feces at the entrance or inside the hive
- Reduced development
- Low productivity
Diagnosis and confirmation
Field methods
- Signs are not specific
Laboratory methods
- Spore microscopy
- PCR for species differentiation
Control and prevention
Good practices
- Improve ventilation and nutrition
- Replace heavily contaminated combs
- Disinfect equipment according to technical guidance
Prevention
- Good ventilation
- Adequate nutrition
- Clean water
- Equipment hygiene
Monitoring
Indicators
- Spore count
- PCR identification
- Nutritional status
Frequency
- When there are signs, losses, or unexplained poor performance