Parasitic Mites & Honeybee Diseases Paul van Westendorp Provincial Apiculturist BC Ministry of Agriculture paul.vanwestendorp@gov.bc.ca

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

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.

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)

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

Varroa on Drone Brood

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).

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.

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

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

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.

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

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 24-48 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

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

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

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

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

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

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

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

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

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

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)

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)

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

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

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.

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

She Needs Help & Protection