Sublethal effects of cyantraniliprole on the development and reproduction of the cabbage cutworm, Spodoptera litura

【Objective】 To study the effects of sublethal doses cyantraniliprole on the development and reproduction of Spodoptera litura in parental and F₁ generations.【Method】 The sublethal doses including both LC₂₀ and LC₄₀ were estimated by the leaf-dipping method and the sublethal effects were investigated in parental and F₁ generations under laboratory conditions.【Result and conclusion】 When the 3rd instar S. litura larvae were exposed to LC₂₀ and LC₄₀ of cyantraniliprole on an arum leave, Colocasia esculenta (L.) Schott for 72 h, the larvae duration from 3rd instar to 6th instar period increased by 2.39 and 4.32 d respectively, and the pupation rate (78.67%, 60.33%) and emergence rate (72.12%, 61.28%) were significantly lower than those of the control groups. Meanwhile, both the male and female pupal mass increased. Compared to the control groups, the laid eggs per female and the hatched rate significantly reduced in the LC₄₀ group, but those did not occur in the LC₂₀ group. No significant differences in pupal duration, sex ratio, and longevity of adults were observed in the treatment exposed to LC₂₀ or LC₄₀ dosages. The parent S. litura exposed to LC₂₀ and LC₄₀ doses of cyantraniliprole also extended the development duration in F₁ generation larvae and reduced the pupation rate, with no significant influence on the emergence rate and the laying eggs per female. These results provide the theoretical basis for developing integrated pest management program for S. litura and the rational use of cyantraniliprole.