I was reading a separate article yesterday regarding oxalic acid. The method in it was comparing applying OA to top bars of the frames at a rate of 3% per hive vs dribble between frames, also at 3% per hive.
Does anyone here know what the hell - 3% per hive - means? It was otherwise a very well structured and well written scientific report. The 3%ph though, is meaningless and completely discredited it to me and I promptly quit reading. If they cannot get the units right then the whole thing is trash. Unless perhaps I am the one needing educating.
A guess, a pretty good one in my opinion:
in Germany, for dribbling, we use a 3,5% oxalic acid / water mixture (usually with sugar in it, but 3,5% OA). For spraying, we use (now may, as it is just being legal) 3,0% watery solution. in Italy e.g. the percentage for dribbling is higher. Probabyl cause they dribble in summer when it doesn`t work so well.
I have read of a commercial outfit where they dribbled on the top-bars repeatedly (in breeding hives). They seemed to be content with the results. The liquid contained sugar.
I once did a block-treatment on some hives with dribbling appr. 50 ml of 3,5% OA in late summer about 3 times with 6 d intervals.. They wintered in less populous than the ones treated with formic acid at the same times. With OAV I would assume a better surving-rate of bees. But I am not finished with experimenting on that. In summer, I still use formic acid as it is faster than my gizmo.