Hi everyone:


Sorry, Just I was busy teaching a couple of q-rearing workshops and on the 
road.

Oxalic acid:

1. I have not really tried that type of evaporizer. So, I can't make 
comments on efficacy. Some of home made evaporizers can heat the oxalic 
acid to a point that OA will be decomposed and become CO2 and H2O.

2. This type of evaporizer and Varroax produce passive OA vapor. This type 
of vapor can't penetrate the cluster when the cluster is tight. This can 
occur when ambient temperature is <5C.
3. Brood can effect efficacy.
4. The machine that we designed uses forced warm air (20C) that can 
penetrate the cluster and expose bees to oxalic acid vapor. It is more 
reliable.

5. Regarding safety. Please read the following paper:
http://www.agroscope.admin.ch/imkerei/00316/00329/02081/index.html?lang=en&download=NHzLpZeg7t,lnp6I0NTU042l2Z6ln1ad1IZn4Z2qZpnO2Yuq2Z6gpJCDeHt,gWym162epYbg2c_JjKbNoKSn6A--

For sure,  OA applicators should take precaution when applying oxalic 
acid. We have many beekeepers using it and we have not had any reports 
regarding safety.


medhat


Medhat Nasr, Ph. D.
Provincial Apiculturist
Crop Diversification Centre North

17507 Fort Road
Edmonton, AB, Canada T5Y 6H3
Tel: (780) 415-2314    Fax: (780) 422-6096
Mailto:[log in to unmask]

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