Cyflumetofen, a novel acaricide – its mode of action and selectivity

Cyflumetofen is a novel acaricide developed by Otsuka AgriTechno Co., Ltd. It affects only spider mites and has no effect on insects, crustaceans or vertebrates under conditions of practical use. The mode of action of cyflumetofen, its selectivity for mites and its safety for insects and vertebrates were investigated.The research showed that cyflumetofen inhibited mitochondria complex II in mites. In addition, the de-esterified form (AB-1) of cyflumetofen inhibited mitochondria complex II at extremely low concentrations. AB-1 was also detected as the main metabolite in mites.The mode of action of cyflumetofen is to inhibit mitochondria complex II by affecting its action site after being metabolised to AB-1. However, inhibition by cyflumetofen and AB-1 in other organisms was very weak. Selectivity for other organisms has contributed to differences in action site activities.