There was some discussion on the Bee-L about drizzling bees with syrup. Some beeks and researchers reported bee losses when they were covered with syrup. The discussion segued into potential problems with oxalic dribble.
I agree with Randy Oliver in that I find no problems with oxalic dribble. It must be pointed out that the sugar concentration probably plays a role in any detrimental effects on the bees. The dribble is very light on sugar in our mix.
Disclaimer: Our oxalic trials are just for research. Oxalic is evidently not approved by the Govt. for honeybee mite treatment.
Oxalic acid is available at hardware stores in small amounts as wood bleach and can be obtained in big bags from Wintersun Chemical.
We take a gallon of distilled, dump half out into another empty gallon jug.
Measure 140 grams of oxalic acid on a paper plate on an Ohaus electronic gram postal scale.
Fold the plate to pour the oxalic into the jug.
Top off the jug with HFCS (already cut with 20 % water (bleach always added))
Pour into garden sprayer
Screw tip tight enough to curtail the spray into a dribble.
Lightly smoke the top bars.
Run the tip in the groove between the bars.
If you counted, it may take a count of two seconds to treat one seam. I don't think 3 seconds would harm the bees if the tip is set right to drizzle.
Randy and I have compared some notes on repeated treatments in spring conditions with fresh bee hatches.
NO problems with treatments every 10 days.
I would highly recommend to any beek to always trial any treatment on a limited number of hives before jumping in whole hog. I heard first hand of beeks burning bees with oxalic, killing hives with thymol in high heat conditions, and similar problems with formic.
After using sticky boards and monitoring mite drops in one particular yard with high mite loads (16 in ether roll which would be about 25 in a wash) I can say with confidence that it does drop the mites. 300 in two days on one hive.
I'm off to give the third treatment this weekend to the one particular (forgotten) yard. I'm down to 6 to 7 mites per ether roll now in this one.
I expect to reach less than 2 mites per roll like our regular production hives this year.
I also think most of beekeepers problems can be mostly eliminated if the beekeeper can keep mite loads very low. That's just an opinion.
The proof is in the pudding.