Resistance amitraz

Chen, A.C., He, H., and Davey, R.B., Mutations in a putative octopamine receptor gene in amitraz-resistant cattle ticks, Vet. Parasitol., 148, 379, 2007. 

More recently, Chen et al. (2007) found two amino acid substitutions (T8P, L22S) in a putative octopamine receptor in amitraz-resistant cattle ticks. Thus, point mutations may play a role in resistance to formamidine pesticides in ticks. 

This new compound was the prototype for several series. From this original structure were developed amitraz (85), chlormethiuron (86), cymiazole (87) and clenpyrin (88), all of which have been used to control OP-resistant strains of B. microplus. Chlordimeform (84) was later withdrawn from sale and amitraz (85) became the market leader. There is... 

These include amitraz (110), prepared from 54, a member of the form amidine class, active against mites and ticks, that have replaced organophosphorus compounds. Notably, amitraz is active against newer strains of pyrethroid-resistant ticks. The reaction of diphenylamine (8) with sulfur in the presence of iodine as catalyst yields the anthelmintic (worming agent) phenothiazone (phenothiazine) (111) (Scheme 24). It is too toxic for human use, though it is an intermediate in the production of antipsychotic drugs. 

Consistent with the above mentioned trend of little MET-I cross-resistance from mites resistant to other types of acaricides, the MET-I resistant strains are, likewise, less likely to confer cross-resistance to other classes of acaricides and insecticides. MET-I acaricide-resistant TSSM strains exhibited little cross-resistance to dicofol, amitraz or chlorfenapyr [97, 103]. In the reverse case, a methidathion-resistant strain of the predatory mite A. womersleyi showed no cross-resistance to... 

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