Sublethal effects of bifenazate on biological traits and enzymatic properties in the Panonychus citri (Acari: Tetranychidae)

Abstract

Panonychus citri, a major citrus pest. In pest management, bifenazate is a novel acaricide with high biological activity against red mites, such as Tetranychus urticae Koch. However, in the field, pests are frequently exposed to sublethal or lethal concentrations of pesticides. At present, its sublethal effects on P. citri have not been reported. Therefore, in order to investigate sublethal effect of bifenazate on biological traits and enzymatic properties of P. citri. The newly emerged females were treated with two concentrations of bifenazate: LC ₁₀ and LC ₃₀, the development and fecundity were observed. The results showed that female adult duration, fecundity, oviposition days, longevity were decrease compared with control, but pre-oviposition period was longer, net reproductive rate ( R ₀), mean generation ( T) were decreased, intrinsic rate of increase ( rm), finite rate ( λ) were decreased in LC ₃₀, however, doubling time was increased. Enzymatic tests showed that CAT, POD, CarE activities were higher in treatments than control. The SOD and GST activities were lower in LC ₃₀ than control and LC ₁₀, the CYP450 activity was decreased with the increasing concentrations. This study demonstrated that low lethal concentrations of bifenazate adversely affected life table parameters, enzymatic properties in P. citri. Therefore, bifenazate has the potential to control this pest.