The joint toxicity of bifenazate and propargite mixture against Tetranychus urticae Koch

ABSTRACT

Bifenazate is a new type of hydrazine derivative acaricide which has been registered in China since 2008. In order to prolong the service life of bifenazate, the joint toxicity of bifenazate and propargite against Tetranychus urticae was evaluated in this study. The results showed that, with the mass ratio of 5:1 for bifenazate and propargite, the cotoxicity coefficient was 137.5, which showed synergistic toxicity to T. urticae. Moreover, when T. urticae was treated by the mixture of bifenazate and propargite (5:1) at the serial concentrations of 20.00 mg/L, 14.29 mg/L, 11.11 mg/L, 9.09 mg/L, and 7.69 mg/L for 24 h, the activities of glutathione s-transferase (GST) in T. urticae were 3.37, 3.64, 3.93, 4.04, and 4.08 mmol/min/mgPro, which were significantly (P < 0.05) lower than those in T. urticae being treated by bifenazate (7.25, 6.82, 6.71, 6.44, and 5.81 mmol/min/mgPro) and propargite (10.13, 9.79, 9.14, 8.93, and 8.44 mmol/min/mgPro) individually at the same concentration, indicating that the mixture showed a joint inhibition effect on the activities of GST in T. urticae. However, the activities of mixed-function oxidase, carboxylesterase, and acetylcholinesterase in T. urticae treated by bifenazate and propargite (5:1) were not significantly different from those treated by bifenazate and propargite individually. This study provided theoretical basis for reasonably application of bifenazate and propargite mixture in T. urticae control.

KEYWORDS:

• Tetranychus urticae
• bifenazate
• propargite
• joint toxicity
• glutathione s-transferase

Acknowledgements

This research is jointly supported by the earmarked fund for China Agriculture Research System (CARS-11-HNCQ) and The Fundamental Scientific Research Funds for Environment and Plant Protection Institute, CATAS (No. 2016hzs1J021).

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This research is jointly supported by the earmarked fund for China Agriculture Research System [CARS-11-HNCQ] and The Fundamental Scientific Research Funds for Environment and Plant Protection Institute, CATAS [No. 2016hzs1J021].