Panonychus citri's sensitivity to three acaricides on black plum

Laboratory toxicity test and field efficacy of three acaricides on Panonychus citri on black plums were conducted.The results showed that the laboratory LC50 of avermectins,pyridaben and avermectins+propargite on P.citri were 0.1596 mgL-1,0.9752 mgL-1 and 23.7307 mgL-1,respectively.Avermectins had the best poisoning effect on the pest.The field efficacy of 5.12 mgL-1 avermectins,64.00 mgL-1 pyridaben or 280.00 mgL-1 avermectins+propargite on P.citri all exceeded 90.00%.The three pesticides all had high lethality to the pest with no phytotoxicity.The b-values of the toxicity regression equations for the three acaricdes differed.The P.citri population sensitivity distributed most evenly with avermectins+propargite,followed by pyridaben and avermectins.It appeared that the laboratory LC50,field efficacy and b-value on the toxicity regression equation could be used as the criteria to evaluate P.citri's sensitivity to acaricides on black plums.