In my notes from the talk by Joel Gonzalez-Cabrera, a researcher in Valencia, Spain, I wrote: "the metabolite DPMF binds to octopamine receptor- similar to octopamine, causes neuroexcitation." This finding originates from cattle tick and spider mite research. 

It is a significant discovery because it means residues in wax would be adding selective pressure for amitraz/DMPF-resistant mites. This would affect the longstanding management priority of rotating treatments. It's possible we should be considering rotating out comb with residues in addition to rotating treatments, particularly in operations observing resistance to amitraz/DMPF. I'm going go all scientist here and say "further research is necessary" to determine how long residues remain in wax and whether resistant mites are more associated with colonies with higher DPMF residues in combs. 

Following this finding, if application method affects residues in comb, application method will also affect selective pressure for amitraz/DMPF-resistant mites. 

It is widely acknowledged there must be a fitness cost to resistance, given resistance has been simmering in the population for a number of years without completely taking over. My guess would be the SNP is also affecting the ability of octopamine to enter cells, but as far as I'm aware, that's undetermined. I wouldn't be surprised if it's the subject of ongoing research somewhere. 

See: 
By: Cai, Ping; Zhang, Yuanyuan; Yang, Mu; Zhang, Chenghao; Li, Mingxia; Xiao, Wei; Xu, Zhifeng; Zhang, Yongqiang
Title: Target identification and acaricidal activity difference of amitraz and its metabolite DPMF in Tetranychus cinnabarinus (Boisduval).
Source: Pest management science
DOI: 10.1002/ps.7500
Document Type: Journal Article
Published: 2023-Apr-10

By: Kita, T (Kita, Tomo); Hayashi, T (Hayashi, Takeshi); Ohtani, T (Ohtani, Tomohiro); Takao, H (Takao, Haruka); Takasu, H (Takasu, Hiroshi); Liu, GY (Liu, Genyan); Ohta, H (Ohta, Hiroto); Ozoe, F (Ozoe, Fumiyo); Ozoe, Y (Ozoe, Yoshihisa)
Title: Amitraz and its metabolite differentially activate alpha- and beta-adrenergic-like octopamine receptors
Source: PEST MANAGEMENT SCIENCE
Volume: 73
Issue: 5
Pages: 984-990
DOI: 10.1002/ps.4412
Document Type: Article
Published: MAY 2017


Tracey, 
Alberta, Canada

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