1. Parasitic Mites & Honeybee Diseases
Paul van Westendorp
Provincial Apiculturist
BC Ministry of Agriculture

2. Honeybee Diseases Varroa Mite ~ Varroa destructor
American Foulbrood ~ Paenibacillus larvae
Chalkbrood ~ Ascosphaera apis (fungus)
European Foulbrood ~ Mellisococcus pluton
Nosema ~ Nosema apis (microsporidian)
Tracheal Mite ~ Acarapis woodi
Sacbrood ~ virus (non-determined)
Viruses ~ KBV, IAPV, DWV, ABPV
Mismanagement ~ Homo sapiens destructor

3. VARROA MITE Not an Insect. Belongs to the Arachnids (crabs, spiders)
8 legs (Insect; 6 legs), specialized mouthparts, flattened body
Obligate, host specific parasite ~ can’t live without the bee.

4. Varroa mite Female lays eggs before capping (d. 10)
F and M mate inside capped cell. M die. Only F emerge
Mite brood cycle just fits in bee brood cycle (21 – 10 = 11 days)
Preference Drone brood (23 – 11 = 12 days)

5. Varroa Detection Methods
Apistan / Checkmite+ / Apivar strip & Sticky Board test for 24 hours
Alcohol Wash One Cup of Bees (~300)
Icing Sugar Shaking Test
Natural Mite Drop Test Board)
Scrape Capped Drone Brood
=> Monitor Regularly to Obtain FACTS. With Facts Make Management Decisions!

6. Varroa on Drone Brood

7. Varroa Mite Controls
Apistan (fluvalinate) / CheckMite+ (coumaphos) / Apivar (amitraz)
Contact nerve poisons, plastic strip formulations
42 days (6 wks) treatment
Formic Acid (FA65%)
5 x 30 ml treatment /5 days, when temperature > 12’C
1 x 150 ml in plastic bag with slits on bottom board
‘Mite-Gone’, ‘MAQS’
Oxalic Acid
One application when there is little bee brood (~ fall)
Dribble method or sublimation (~ vapour)
Drone Brood Removal Method
Screened Bottom Board (>40% control).

8. AMERICAN FOULBROOD ~ AFB
Paenibacillus larvae (formerly Bacillus larvae)
Spore-forming bacterium, spores viable for decades
Infects and kills bee brood.
Highly contagious: Spores spread by adult bees, infected hive equipment, humans and tools
Antibiotic-resistant strains ~ r-AFB
Among the most destructive bee diseases worldwide.

9. AFB Symptoms Perforated caps of brood cells
Brood frame has “shotgun” appearance

10. AFB Symptoms Examine brood frame at angle of 15 degrees
Light source (~sun) behind you
Look for scale deposit on the bottom side of brood cells
Some cells have larval tongue sticking up, but not always

11. AFB Symptoms Select brood cell with discolored larval remains
Insert toothpick and slowly withdraw
Slimy cell contents shows “ropiness”
Place slime and toothpick in plastic bag or wrap
Submit for microscopic examination.

12. AFB Controls Familiarize with symptoms, know what to look for!
Examine brood frames regularly few weeks)
Remove brood frames with visible signs and burn
When several frames with symptoms, shake bees onto new frames. BURN old frames.
Adopt hygienic management practices:
Reduce equipment exchange
Replace 20% brood frames annually (~5 year replacement cycle)
Establish “hospital apiary”
Clean hive tools, coveralls, hands

13. AFB Controls ONLY apply Antibiotics when needed
Oxytetracycline (Oxytet), Tylosin (Tylan)
DO NOT apply drugs prophylactically
Do you take any antibiotics as a prevention to future infection?
Antibiotic applications:
Always READ label instructions before use
Don’t Overdose or Underdose: Use correct amounts!
When infection during honey season – remove honey supers, sprinkle icing sugar mix on top bars and re-install honey supers hours later. Repeat after 3 weeks.
Infection outside honey season (in spring or fall) – apply medicated sugar syrup solution
Do Not use Antibiotic Extender Patties

14. EUROPEAN FOULBROOD -EFB
Caused by Mellisococcus pluton, followed by Pseudobacillus alvei
Only affects larvae that die before pupal stage
Twisted appearance, discoloration of larva, NOT ropy like AFB

15. EFB Symptoms Irregular bee brood appearance
Caps NOT punctured like AFB-infected brood

16. EFB Symptoms Young larvae in the bottom of cell, discolored
Older larvae discolored and twisted

17. EFB Controls EFB is Stress related; apply “TLC” to your bees
Effective control with antibiotics: icing sugar or syrup

18. CHALKBROOD Caused by fungus, Ascosphaera apis
Only affects bee brood; mummifies larvae

19. Chalkbrood Mummies often on bottom board and front of entrance
Mummy can be white (asexual) or black (sexual reproduction)

20. Chalkbrood Control No Chemical / Drug controls available
Best control through Hygienic Impulse of bees: replace queen with new queen of hygienic stock
Reduce moisture built-up; improve aeration, raise colony off the ground, screened bottom

21. NOSEMA Caused by microsporidian fungus, genus Nosema
Only affects adult bees, mainly in spring: dysentery-like
Bee faeces on frame and hive surfaces

22. Nosema Disease Nosema apis and Nosema ceranae
Infects the epithelial cell wall of the bee gut: plugs up the cell wall, bee deprived of nutrients

23. Nosema Diagnosis & Control
Sample of bee faeces or adult bees => send to lab
Haemocytometer; # spores/square = level of infection
When 2 m spores / bee: Apply Fumidil (fumagillin antibiotic)

24. TRACHEAL MITE Acarapis woodi, microscopic
“Isle of Wight” – disease 1919
Only affects adult bees
Entire life cycle in bee trachea
Plugs up breathing tubes causing lethargic bees and reduced life-expectancy
Generally doesn’t cause colony death but may when other disease present (~Nosema)

25. Tracheal Mite Diagnosis & Control
Microscopic examination of trachea; time consuming,
Most control through resistant bee stock
Only affects bees in spring and fall
Formic Acid / menthol crystals effective controls

26. SACBROOD Sacbrood caused by virus Stress related
Symptoms similar to EFB but antibiotics not effective
Removal of larva is liquid-filled sac
Generally not persistent
Queen replacement often recommended

27. HONEYBEE VIRUSES Bee Viruses:
Kashmir Bee Virus ~ KBV
Acute Bee Paralysis Virus ~ ABPV
Deformed Wing Virus ~ DWV
Israel Acute Para. Virus ~ IAPV
Young bees transparent, oily, sweaty, “drunk” and crawling
No drugs/medicine available
Increase incidence attributed to Varroa and Tracheal Mites
Most common in late spring/early summer
Colony weak and bees often slow, non-active.

28. MISMANAGEMENT Responsible for most colony failure: Starvation
Undetected disease, untreated disease
Controls applied too late or at wrong time
Poor winter preparation
No hygienic management practices
Lack of knowledge about life cycle of pathogen and how it relates to cycle of honeybees
Under-dosing /Over-dosing of drugs and chemicals
No brood frame replacement program
Insufficient monitoring

29. She Needs Help & Protection