Abstract:  In order to clarify the sublethal effects of scopoletin on the experimental population of Tetranychus cinnabarinus (Boisduval), and provide the theoretical basis for the further development and application of scopoletin used as a plant-derived acaricide, we used the leaf disc bioassay to evaluate the effects of scopoletin at sublethal dosages on F₀ and F₁ populations. The results showed that the fecundity of female adults treated with scopoletin at three sublethal dosages (LC₄₀, LC₃₀ and LC₂₀) was increased by 73.82%, 186.97% and 70.18%, respectively, while the longevity, oviposition duration and frmale-to-male sex ratios were not affected. The duration of oviposition, larval and nymphal stages was not significantly different from that of the control (P>0.05), but the adult period and female longevity were shorter than those of the control. The F₁ generation displayed shortened oviposition duration, reduced fecundity and decreased the proportion of females when compared with the control. The net reproductive rate (R₀) dropped from 50.5976 to the lowest 33.9910, the mean generation time (T) and population doubling time (Dt) were all shorter than those of the control, and fitness defects appeared in all three treatment populations. The results indicate that scopoletin treatment at sublethal dosages can reduce the development and reproduction rates of T. cinnabarinus populations, and this provides positive evidence for application of scopoletin in pest management.

Key words: Tetranychus cinnabarinus, scopoletin, contact toxicity, sublethal effect, life table, growth and development, reproduction