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Parasitic Mite Syndrome (PMS)

Division of Plant Industry – Apiculture
8995 East Main Street 
Reynoldsburg, Ohio 43068-3399



Upon examination of your honey bee colonies’ brood, you observe symptoms that might resemble EFB, AFB and/or Sacbrood disease. However, you are not sure what the problem is, because they are not the characteristic disease symptoms with respect to each disease; they may be a combination of symptoms from all three brood diseases. Also, the colony is infested with the Varroa and/or Tracheal mites.

The USDA, Bee Research Laboratory in Beltsville, Maryland calls this condition parasitic mite syndrome (PMS). PMS is thought to be caused by a secondary infection as a result of the mite infestation. Presently no known pathogen has been found to be predominant. The following are adult and brood symptoms that may be observed in the colony.

Adult Symptoms

  1. Varroa mite present
  2. Bee population reduction
  3. Crawling adult bees
  4. Queen supersedure
  5. Tracheal mite may or may not be present
Brood Symptoms
  1. Varroa mite present
  2. Spotty brood pattern
  3. Affected brood from the ‘C” stage larva to the prepupa stage
  4. Larva may be twisted and light brown in color – no ropiness
  5. Scales observed, but are not brittle and difficult to remove like AFB
  6. An odor is not evident
When determining if a colony has PMS, comb samples should be taken in preference to a smear. The Bee Research Lab recommends sending a piece of comb about 2 x 2 inches, loosely wrapped in paper, and send also about 100 adult bees from the same colony.
Prepared by: Gordon Rudloff
State Apiarist
Ohio Department of Agriculture
H. Shimanuki, N. W. Calderone and D. A. Knox 1994