Sublethal effects of diflubenzuron on the growth and reproduction of an experimental population of Tetranychus cinnabarinus (Boisduval) (Acari: Tetranychidae)

Author of the article:XIN Tian-Rong； LIAN Tao；LI Xue-Er；WANG Jing；ZOU Zhi-Wen；XIA Bin

Author's Workplace：College of Life Science, Nanchang University, Nanchang 330031, China；College of Life Science, Nanchang University, Nanchang 330031, China；College of Life Science, Nanchang University, Nanchang 330031, China；College of Life Science, Nanchang University, Nanchang 330031, China；College of Life Science, Nanchang University, Nanchang 330031, China；College of Life Science, Nanchang University, Nanchang 330031, China

Key Words：Tetranychus cinnabarinus; diflubenzuron; sublethal effects; life table; toxicity

Abstract：[Objectives]  To evaluate the sublethal effects of diflubenzuron on the development and reproduction of Tetranychus cinnabarinus. [Methods]  The leaf disc dipping method was used to investigate the sublethal effects of diflubenzuron on the development and reproduction of a laboratory population of T. cinnabarinus. [Results]  The LC50, LC30 and LC10 of diflubenzuron on the eggs of T. cinnabarinus were 15.825, 6.089 and 1.534 mg/L, respectively. Compared with the control group, treating eggs with a sublethal dose (LC10 and LC30) of diflubenzuron did not result in a significant difference in the duration of either the larval period, or that of the protonymph or deutonymph, but the egg period and quiescent duration were significantly prolonged. The hatching rate, larval and the nymph survival rate, number of eggs laid and mean female life span, were all decreased by sublethal exposure to diflubenzuron. The LC30 treatment group had a significantly longer pre-oviposition period and significantly shorter oviposition period than the control group. The net reproductive rate (R0) of all treatment groups was significantly lower than that of the control, with that of the LC30 group being the lowest. The intrinsic rate of increase (rm) and the finite rate of increase (λ) of all three treatment groups decreased, but only that of the LC30 group decreased significantly. The doubling time (Dt) of the LC30 group was significantly prolonged. There was no significant difference in the mean generation time (T) and sex ratio of the treatment groups and that of the control. [Conclusion]  Different sublethal concentrations of diflubenzuron have significant inhibitory effects on the longevity and fecundity of T. cinnabarinus.