After our fall treatments for mites, which consisted of thymol cream, formic meat pads, and one "hard" treatment plus lots of feeding of HFCS, we shipped our singles and some doubles to Florida in November. The bees look great. No Fumidil ever in 30 years.
The bees now shipping to Cal. look fabulous too, with very little drop on the bottoms. Much better than most years.
After some research, some email with Randy Oliver, we gave Oxalic treatments a go over the last two weeks in the Florida panhandle. I instructed(I'm still in Michigan for one more day) JJ and the crew to apply oxalic drip to one half of every yard. That's 40 hives out of 80 for every yard. We did some mite rolls 4 days later and are rolling(ether roll) 0 to 2 mites in the hives treated with the dribble of 5 ml per slot applied with a dosing gun we bought from Jeffers. We thinned out syrup with water in a 5 gallon bucket and added 700 grams of acid. Thinner syrup applies easier with a dosing gun.
The untreated side had about 3 to 8 mites per roll. They have been brooding since mid Nov., so they had about 6+ weeks of brooding. JJ reported some brood damage along the top bars, but was of the opinion that it was inconsequential.
My friend Steve Cantu reported that he tried oxalic some years ago and the help improperly mixed the acid in a very high concentration and burned the wings off the bees.
We will follow up and treat the other side of each yard.
Our next treatment will be Formic soaked meat pads.
Last year the mite population got a bit out of hand and it's hard to catch up once splitting and honey making starts.
Mix powdered oxalic acid (available as wood bleach in hardware stores or by the 50 # bag for about $300) with distilled water and sugar (a light syrup)to make solutions at 3.5% strength. We use a small digital scale to weigh the acid.
For small batches mix 140 grams oxalic with 1 gallon of distilled water and enough sugar or fructose to make a light syrup. 140 grams divided by 3785 grams of water (one gallon) = 0.036 or 3.6 % strength. The bees will lick it up.
It will keep for a bit in cooler weather. It's so cheap we just make up new batches.
You can get a doser from Jeffer's supply, but we use a small pump up sprayer and close the tip off until it dribbles. Pick up a small medicine cup from the drug store and practice dribbling off 5 ml. Apply 5ml per seam of bees by running the tip of the sprayer between the frames. Avoid putting much more than 50 ml total per hive.
We have done double deeps and surpassed that amount with no apparent harm however.
It is reported that treatments done in the fall should be limited to only one or the bees health could be compromised.