Toxicity of the acaricide bifenazate to the predatory mite Phytoseiulus persimilis (Acari: Phytoseiidae) and the feasibility of using bifenazate in conjunction with P. persimilis to control the two-spotted spider mite Tetranychus urticae (Acari: Tetranychidae)
Author of the article:GONG Ya-Jun** JIN Gui-Hua CUI Bao-Xiu WANG Ze-Hua ZHU LiangKANG Zong-Jiang WEI Shu-Jun***
Author's Workplace:Institute of Plant and Environmental Protection, Beijing Academy of Agriculture and Forestry Sciences, Beijing 100097, China
Key Words:Phytoseiulus persimilis, bifenazate, Tetranychus urticae, biological control, combined control
Abstract:
[Objectives] To assess the toxicity of the acaricide
bifenazate on the predatory mite Phytoseiulus
persimilis (Acari: Phytoseiidae), and evaluate the feasibility of using
this acaricide in conjunction with P.
persimilis to control the two-spotted spider mite Tetranychus urticae (Acari: Tetranychidae). [Methods] The effect of
bifenazate on the fecundity and mortality of adults and nymphs of P. persimilis, and the efficacy of a combination of P. persimilis and bifenazate in controlling T. urticae were tested in the laboratory. [Results] At a concentration
of 143 mg/L, bifenazate had no effect on the mortality and fecundity of P. persimilis.
Adult and nymph mortality were 2.30% and 2.04% respectively after 96 h. The
treatment group had an average fecundity of 15.08 eggs per female, which was
not significantly different to that of the control group (15.45 eggs per
female). The average hatchability of the treatment group was 98.63%, which was
also not significantly different to that of the control group (98.13%). A
combination of bifenazate and P.
persimilis resulted in fast and persistent control of T. urticae, with a control efficacy of 97.35% after 2 d and 100% after
18 d. [Conclusion] Bifenazate does not affect P. persimilis but is effective against T. urticae. The combined use of
bifenazate and P. persimilis is
effective in controlling T. urticae.