ABSTRACT Chlorantraniliprole (CAP), a novel anthranilic diamide insecticide, has been extensively used in agricultural pest management. Given their environmental persistence, low‐concentration CAP residues warrant a systematic assessment of their safety risks. The silkworm ( Bombyx mori ) is the lepidopteran model insect. This study was conducted to characterize the changes in Ca 2+ levels and the expression of the molting‐related gene Ftz‐f1 in the midgut of fourth‐instar B. mori after exposure to low‐concentration CAP at different time intervals (CAP 0–24 h, CAP 24–48 h, and CAP 48–72 h). Low‐concentration CAP exposure significantly reduced the molting rate of fourth‐instar silkworms in the CAP‐exposed groups to 97%, 92%, and 80% of the control group, respectively ( p < 0.001), and the percentage proportion of newly molted fifth instar in the CAP‐treated groups to 92%, 82%, and 67% of the control group, respectively ( p < 0.001). CAP exposure disrupts intracellular Ca 2+ homeostasis and induces dysregulation in the transcription of Ca 2+ ‐regulating genes, consequently suppressing both transcription and protein expression of the molting target gene Ftz‐f1 , which ultimately leads to molting defects in silkworms. The present study reveals the molecular mechanism of the impaired molting of fourth‐instar molting defects caused by low‐concentration CAP exposure, which provides critical evidence for the safety evaluation of low‐concentration CAP residues and the sublethal toxicity to the lepidopteran insect.
Chen et al. (Thu,) studied this question.