The effect of a new acaricide, phenothiocarb (S-(4-phenoxybutyl)N,N-dimethyl thiocarbamate) [on Panonychus]

Phenothiocarb has been developed by Kumiai Chemical Ind. Co., Ltd. under the code number of B1-5452 as a new acaricide with low toxicity to mammals, fish and beneficial insects. It is effective on mites belonging to Panonychus. The LC-50 values of phenothiocarb for eggs. larvae, protonymphs, deutonymphs and female adults of P. citri were 8.9, 12.6, 15.2, 32.8 and 81 ppm, respectively. Its acaricidal activity varied according to the temperature at which it was tested. Activity at a low temperature (15°C) was higher than that at a high temperature (30°C). Phenothiocarb was very effective against not only a susceptible strain but also the dicofol or benzoximate resistant strains of P. citri. In field trials conducted for 3 years phenothiocarb sprayed at a concentration of 233-500 ppm showed an efficacy equal to dicofol and amitraz for the control of citus red mite. The control effect in the field was better in autumn than in summer.