Christine said:



 I am puzzled by Randy's comment to Allen that amitraz doesn't penetrate wax cappings.

 Your are correct wax is the sink to most lipophelic chemicals  such as Amitraz,, fluvalinate, etc.



In spite residues found in wax, the levels are not high enough to kill developing stages of mites in capped cells.



In fact Milani developed a test to measure toxicity of chemicals or resistance to miticides by adding miticides to wax and expose mites to the treated wax for 24 hrs to determine LD50. This is a contact exposure.



 In cases like formic acid, it  can penetrate the cell capping that is made of wax and pollen. If the fume concentration is high enough, it can kill male mite as observed in MAQS application.



Moreover, levels reported by those papers did not mention what type of application or dose these chemicals applied to be colonies and for how long been applied.



In my lab we just finished analysis of honey samples from bee colonies treated with Apivar for 4 consecutive years, most honey samples were zero and few with 1- 50 ppb. We applied apivar  as a single treatment in spring with 2 strips. This show proper use does not leave those horrific levels. My wax samples are being tested.

Medhat

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