[Jeyster]

I've got two hives started from packages last spring. One was strong all summer and even made 30lbs of fall honey, the other struggled all summer. I treated the weak on in the fall, but for various reasons didn't get around to treat the strong one.

Fast forward to last week. Both hives still living and true to their nature; one strong and active, the other with fewer bees and not very active. I did a 24hr mite drop test with the following results: strong =79, weak=7.

Alarmed, I decided to do another on the next warm day. Today I counted the following: strong=7 (yes seven), weak=3.

What would the account for the big difference? The first count was the first really warm day and the bees were super active. Yesterday/today was nearly as warm, but windy and not as much activity outside the hive.

 

[Dave Burrup]

That is a good example of why 24 hr mite drops are unreliable. An alcohol wash will give you better results.
Dave

 

[Joseph Clemens]

Aren't the two different colonies, different in population and amount of brood? If they are, then shouldn't the number of mites vary with the size of the bee population, and the size of the brood nest, and the age of the brood, etc.? Isn't what you're really trying to determine: what is the population of Varroa in relation to the population of honey bees.

 

[Ray4852]

You have mites treat. One mite is to many

 

[Honey-4-All]

The infestation rate is the number you are looking for. The only way to find that is to count bees and then count the accompanying mites. A good sample is 2-300 out of middle of the brood chamber testing bees that are of varied age.

 

[AR Beekeeper]

Mites enter and leave brood cells every day. How many are groomed off or simply fall depends on the numbers that are on the bees versus in the cells. That is why a three to seven day count is better than just one day, you will get an average that is more accurate than just one day.

Most of the literature now recommends the 300 bees in a jar sample, but that will depend on which frame you get the sample from. It is best to take the sample from the brood nest, and to always take the sample from the same frame. This gives a consistent chance that the numbers are accurate.