Honey Bees

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Jump to: Powdered Sugar Shake | Alcohol Wash | Ether Roll | Sticky Board | Uncapping Drone Brood

Varroa Monitoring

Performing Mite Checks

Choose a method to use consistently. How many varroa are present, and what is your threshold for treatment?

Perform checks 4 times a year, particularly between July and October when your bee population is at its peak and as it decreases before winter.
Also check 1 week after treatment to check treatment efficacy.

Sampling Adult Bees

Mite counts can be done during a hive inspection by collecting approximately 300 adult bees (about ½ cup) in a mason jar or mite check kit. You can then either coat the bees in powdered sugar (non-lethal), wash with alcohol (lethal), or spray with ether for 1-2 seconds (lethal). Divide the number of mites you count by 3, and then you have your mite level in percentage form.

# of mites / 3 = % mite load

There isn’t necessarily a “magic number” but as a general guide it’s acceptable to have ≤2% and controls should be applied at ≥3%. 

Powdered Sugar Shake (non-lethal)

  1. Coat bees with about 1-2 Tbsp powdered sugar.
  2. Shake 1 minute.
  3. Wait 3-5 minutes for mites to drop.
  4. Shake powdered sugar onto a white container.
  5. Count your mites.
  6. Return your sugar-coated bees back to the hive.
 

Alcohol Wash (lethal)

  1. Add enough alcohol to the jar to submerge your bees.
  2. Shake 1 minute.
  3. Pour through a screen into a white container, so that the alcohol and mites pass through but the bees stay in the jar.
  4. Count your mites.
  5. Discard sampled bees.
 

Ether Roll (lethal)

  1. Spray in the jar for 1-2 seconds with starter fluid.
  2. Shake for 1 minute.
  3. Roll the jar, so that the mites stick to the sides of the jar.
  4. Count your mites.
  5. Discard sampled bees.
Sticky Board

A non-invasive (though less accurate) way to check mites is to use a sticky board under a screened bottom board to capture fallen mites. Take a piece of coated cardboard and coat it with Pam cooking spray or Vaseline. Place under your screened bottom board where the solid insert would typically go and leave for 48-72 hours. Remove and count your mites. The board itself can be scraped clean and reused.

Uncapping Drone Brood

Varroa have a preference for drone brood over worker brood. You can smoke and open your hive as usual, then select a frame of drone brood. Make sure the queen isn’t present, if she is then gently place her back into the hive. Shake the adult bees back into the hive and pierce drone brood with a capping scratcher. Since the pupae are white, the varroa mites should be clearly visible. Try to examine about 100 drone brood. If you see 5 or more varroa mites, consider treating. You can place the frame back into the hive and the workers will clean it up. The drone brood makes a tasty snack for chickens, and this method doesn’t have much affect on the overall colony health since the drones aren’t contributing members of your hive.

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