I wanted to post an update with my success of using Randy Oliver's Shop Towel ratio experimentation "With a legal experimental use permit". Randy continues to do some great work on determining the exact amounts of Oxalic Acid (OA) required to achieve the desired results of eliminating Varroa. Here is Randy's Update Page
I have been using Randy's basic recipe/ratio for the shop towel method with great success. But I have modified the method of application to replicate Maggie's success in Argentina (Paper is here) I have been hanging the towels between the frames rather than laying them on top.
Since I am a sideliner with only about 20 hives, I am am able to take the extra time to prepare the shop towels, and then individually fold them in preparation for hanging them in the hive. I hang the towels with wooden toothpicks (the images below show nails, but they were not necessary) vertically between the frames. I am experimenting with how many towels are required, and Randy's experimentation on the amount of OA in the hive is refining this number, but I feel like one hanging sheet per 5 frames is about right.
This method has taken my mite counts down to 0-1 per 300 bees in August in NE Florida with no other treatment methods being applied. I believe this method of application solves the issue of not being able to reach mites under the caps because the OA stays in the hive until the bees chew it up or remove it, which seems to take about 2-3 brood cycles. I have found strips still hanging in the hive up to 8 weeks after application.
The current recipe I am using for creating the shop towels is:
Half roll of shop towels (Full roll cut in half with kitchen knife): 55 half-sheets per roll plus cardboard tube ~ 56 sheets
350g OA total = 6.25g OA per half sheet
350ml Vegetable Glycerin = 6.25ml glycerin per half sheet
280ml Water = 5ml Water per half sheet that will evaporate (the water aids in the absorption of the OA into the towel)
These measurements are for soaking the entire half roll of shop towels so that each towel gets the listed amounts of OA per sheet. By knowing the exact amount of OA per sheet you can more accurately know the amount of OA you are putting in a hive for efficacy. For example, in a 10 frame box if you hang two towels you are putting 12.5g (6.25g x 2)of OA in the hive, and if you hung three you are putting 18.75g (6.25g x 3) in the hive.
Warm up glycerin (I use a hot plate and old pot)
Add OA to warm glycerin (keep below 160 deg F)
Add water to mixture (I like to use the water to clean out my OA from the beaker or measuring cup)
Soak half roll with mixture (I flip the towel once to absorb liquid on both sides evenly)
And here are some pictures to help understand how I fold and hang the towels:
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And in keeping with good legal science, as Randy continues to say:
Warning: this method of treatment is only approved in some countries, but not yet registered in others, including the U.S. It is illegal to apply oxalic acid to a hive in this manner unless it is registered for use in your jurisdiction. However, you may be able to obtain an “Experimental Use Permit” or a “Pesticide Research Authorization” from your State Lead Agency for pesticide regulation.
I have been using Randy's basic recipe/ratio for the shop towel method with great success. But I have modified the method of application to replicate Maggie's success in Argentina (Paper is here) I have been hanging the towels between the frames rather than laying them on top.
Since I am a sideliner with only about 20 hives, I am am able to take the extra time to prepare the shop towels, and then individually fold them in preparation for hanging them in the hive. I hang the towels with wooden toothpicks (the images below show nails, but they were not necessary) vertically between the frames. I am experimenting with how many towels are required, and Randy's experimentation on the amount of OA in the hive is refining this number, but I feel like one hanging sheet per 5 frames is about right.
This method has taken my mite counts down to 0-1 per 300 bees in August in NE Florida with no other treatment methods being applied. I believe this method of application solves the issue of not being able to reach mites under the caps because the OA stays in the hive until the bees chew it up or remove it, which seems to take about 2-3 brood cycles. I have found strips still hanging in the hive up to 8 weeks after application.
The current recipe I am using for creating the shop towels is:
Half roll of shop towels (Full roll cut in half with kitchen knife): 55 half-sheets per roll plus cardboard tube ~ 56 sheets
350g OA total = 6.25g OA per half sheet
350ml Vegetable Glycerin = 6.25ml glycerin per half sheet
280ml Water = 5ml Water per half sheet that will evaporate (the water aids in the absorption of the OA into the towel)
These measurements are for soaking the entire half roll of shop towels so that each towel gets the listed amounts of OA per sheet. By knowing the exact amount of OA per sheet you can more accurately know the amount of OA you are putting in a hive for efficacy. For example, in a 10 frame box if you hang two towels you are putting 12.5g (6.25g x 2)of OA in the hive, and if you hung three you are putting 18.75g (6.25g x 3) in the hive.
Warm up glycerin (I use a hot plate and old pot)
Add OA to warm glycerin (keep below 160 deg F)
Add water to mixture (I like to use the water to clean out my OA from the beaker or measuring cup)
Soak half roll with mixture (I flip the towel once to absorb liquid on both sides evenly)
And here are some pictures to help understand how I fold and hang the towels:
And in keeping with good legal science, as Randy continues to say:
Warning: this method of treatment is only approved in some countries, but not yet registered in others, including the U.S. It is illegal to apply oxalic acid to a hive in this manner unless it is registered for use in your jurisdiction. However, you may be able to obtain an “Experimental Use Permit” or a “Pesticide Research Authorization” from your State Lead Agency for pesticide regulation.
