OAG, OxalicAcidGlycerol is a very promising treatment against varroa parasite. Filling the need to treat in spring when most mites are hidden in the brood and in the same time not contaminating coming crop with unwanted chemicals.
In the US there is great need of finding methods that would replace labor intensive multiple treatments with Oxalic sublimation (gas). Randy Oliver who has done extensive research on different proportions OxalicAcid:Glycerol argues that the treatment with pads 18gOA/14mlGlycerol has full effect after 50 days. Using a 50/50 mixture on absorbent “towels”.
Here we have made a small study under our conditions:
Home Apiary 5 colonies. We checked all colonies with BeeScanning app.All but one colony had 0% infestation. Colony nr 42 had 1%.
We decided to treat 3 colonies with OAG pads placed on top of brood chamber frames. Doses were 18g OA (0,5g/cm2). Substrate paper quality thickness 0,3 mm used for herbarium. Counting mite drops every 24 hours.
Questions we like to adress:
1. Is the OAG effective?
2. What is the ratio between app and OAG findings? Can we rely on the app, for practical needs?
Conclusions so far:
In an apiary there is great variation in varroa infestation. This may question the thesis that there is great reinfestation occurring.
With BeeScanning app you can readily identify both colonies with low infestation (of interest for breeding) and with high infestation in need of care.
OAG is very effective in killing mites, both forensic, already out on the bees and newly released from hatching bees. In the period measured nr 42 has released more than 1000 mites falling to the bottom in 2 weeks. In the first 3 days forensic mite drops were about 100/day rest from hatching, following period about 60/day were released and killed. Eventually we will receive 0 droppings?
1. Yes very. The curve is suggesting close to 100% kill off. Lets follow up.
2. 1% equals 200-300 mites/with beestrength 20000-30000 bees. Seems reasonable enough.
Bees don’t seem to be very stressed about the OAG pads ( as opposed to behaviour seen with Thymol). There are tendencys chewing away the pads but on a very slow rate.