Standardized alcohol wash for mite counts

[Fusion_power]

Randy Oliver published in American Bee Journal his method for performing an alcohol wash on all of his colonies of bees. His objective is to find and breed from colonies that have extremely low mite levels. A short summary of the method is to take mid-summer alcohol washes, identify the colonies with very low mite counts, also identify the colonies with very high mite counts, move the low count colonies to breeding yards, and treat the high count colonies to prevent mite bombs from collapsing and spreading mites to other hives. The hives being measured were set up as spring nucs and have had at least 3 months for mites to increase.

Randy is not using the USDA method for identifying VSH colonies The USDA method is to uncap cells to find total number of mites in cells and number of non-reproductive mites. The ratio of mites that are not reproductive relative to the number that are reproducing determines how many VSH alleles are present in the colony. This chart shows the relationship.

% non reproducing mites | VSH alleles | VSH %
100 | 4 | 100 (these are the goal, 100% VSH bees)
67 | 3,5 | 87,5 (these are high value breeding queens)
50 | 3 | 75 (these also are breeding material, but will take more work to stabilize the traits)
33 | 2 | 50 (any less than this has little breeding value)
25 | 1 | 25
20 | 0 | 0

Since many beekeepers on this forum are familiar with arista, here is a link to a document describing the methodology.

https://aristabeeresearch.org/wp-co...le-Drone-project-2014-Results-11-feb-2015.pdf

Now my question for you is this. Randy Oliver is trying to identify colonies with very low mite counts. The USDA method identifies colonies with high percentages of non-reproductive mites. Is Randy Oliver actually identifying VSH colonies? Or is he finding some other trait(s)? Can you spot the weaknesses of his method?

 

[Finman]

.
Hmmm. Randy counts mites. I am not interested about his methods.

 

[SDM]

A single monitoring of mite levels doesn't show how the colony is managing mites. It just gives the picture on the day. Surely he'd need to monitor over a longer bood period to know if the were controlling their mite population.

 

[SDM]

A single monitoring of mite levels doesn't show how the colony is managing mites. It just gives the picture on the day. Surely he'd need to monitor over a longer bood period to know if the were controlling their mite population, or at least have a figure from when the nucs were made up.
He could just as easily be selecting for bees with low levels of robbing as those with high mite levels may have entered the hives of other keepers.
I guess the likelihood is it would slowly improve the ability of his bees to cope with mites but equally he could take 2 steps forward and 1 or 2 back.

 

[Beefriendly]

The ratio of mites that are not reproductive relative to the number that are reproducing determines how many VSH alleles are present in the colony. This chart shows the relationship.

This is the bit I find puzzling. VSH is meant to indicate that bees are finding uncapping and removing larvae infected with varroa. Yet these tests for VSH are more to do with counting mites that are present inside cells and dividing them into reproducing vs non reproducing.
Are they counting them at stage prior to uncapping and removal? If some varroa inside cells are non reproductive does that mean a different mechanism is working to make them non reproductively viable?
Simple explanations would be appreciated.

 

[Finman]

.
Simple rearing can be used, when you monitor what is the difference with ordinary hive and antivarroa hive.

Results are shown as monthly curves. Results may show that infestation rate is 10% lower than in ordinary hive.

When mite doubles itself in one month, 10% tells that VHS hive has some days slower mite reproduction. And that means nothing in practice.

What is the reason to low infestation, it is another question.

Next question is, is this bee stock at alive level or is it able to forage surplus.

Next question is, does it compete in productive honey prodction with ordinary bees.

And more questions: Can you nurse them? Too angry, too small colony, too small winter cluster, odd habits like Russian bee, too swarmy...

F1 generation loses VSH ability, and it makes impossible to keep them. Too expencive to buy new queens.

Many questions, and to where are you answering

.you can call bees VSH , hygienic and what ever as long as it revieles out that there is no difference with normal bees. ..as it has happened in practice.
.

 

[Fusion_power]

I'll put in the answers I know and pose a few issues that are not addressed in the article.

He is retesting the presumed mite resistant colonies. A single test with low mite levels does not prove nearly as much as 2 or 3 tests over a period of months each of which shows low levels.

The weakness with this type evaluation is that the starting number of mites is unknown. A nuc that starts with 1000 mites could double 3 times with the result it tests as a mite bomb with 8000 mites just waiting on hive collapse to spread mites far and wide. Given that the hives from which the nucs are set up have variable numbers of mites, the predictable result is that the nucs will also have variable numbers. With his treatment program, it is highly likely that some nucs are set up with very low levels of mites. These nucs might still have very low numbers of mites when tested yet not be mite resistant to any measurable degree.

One way to overcome the variability in starting number of mites is to use mite challenge tests. This involves placing a known number of mites into a colony and watching to see how the bees handle them. Performing challenge tests with 1000 or more colonies would be very time consuming. Presuming the mite counts identify 50 or fewer colonies with very low mite counts, it is much more feasible to move bees and/or brood from highly infested colonies into the possibly resistant colonies and then check a few months later to see if mite counts grow or are reduced.

There is also the factor that some colonies might rob out a mite bomb while other colonies are genetically averse to robbing. The robbing colonies could pick up a huge load of mites in a short time while the non-robbers would stay relatively stable. As noted above, he may be selecting for non-robbing colonies instead of truly mite resistant colonies.

Finman, you might be pleased with the bees Randy keeps. He is breeding from lines of Italians selected for California almond pollination followed by honey production in the grass valley area. They would fit your description of large overwintering colonies with high honey production potential.