Christina said:
It seems to me that for small-scale beekeepers the organic acids and thymol are better options, especially where treatment is not well standardized (i.e. people don't follow instructions).
No one can argue with the above statement as long as requirements met for the product used. Temperature ranges (formic acid and Thymol), and No brood (oxalic acid; Not registered in the USA) requirements must be met and label's instructions should be followed. Thus a beekeeper can achieve effective control of varroa.
From research and experience, most of the time the weatherman's forecast is not correct and beekeepers have different priorities (Not Bee Baby setters!). Consequently results are variable to control mites.  By the way, I have some dedicated beekeepers who would not use synthetic acaricides but they use alternatives. They are happy with that type of application, cost of time and accept their losses.

For acaricide users, synthetic acaricides are contact and don't require temperature ranges. They leave residues but it can be mitigated as discussed. Beekeepers have the choice to use them. Amitraz as any other agrochemicals (pesticides and antibiotics, etc.) are regulated.  Residues must not exceed the MRLs. Amitraz is used in other commodities and  different MRLs have been set for each commodity. Food Safety Agency's job is to monitor the residues to protect consumers.

Whenever you handle chemicals protect yourself first! Beekeeper s' safety is first!


Medhat

Dr. Medhat Nasr
Alberta Provincial Apiculturist
Pest Surveillance Branch
Crop Research and Extension
Agriculture and Rural Development
17507 Fort Road NW
Edmonton, AB T5Y 6H3 Canada
Tel: 780-415-2314             Fax: 780-422- 6096
E-mail:  [log in to unmask]
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