Mechanism of Ca2+ in regulating pupation defects of Bombyx mori after exposure to chlorantraniliprole

Chlorantraniliprole (CAP) is a novel amide insecticide widely used in
agriculture. Trace residues of CAP in the environment pose a threat to the
development and metamorphosis of the silkworm (Bombyx mori). However, the
mechanisms by which CAP exposure disrupts insect metamorphosis remain
poorly understood. This study investigated the levels of intracellular
Ca²⁺ and 20-hydroxyecdysone (20E) following exposure to low concentrations
of CAP. The results revealed that CAP exposure both directly caused
increased Ca²⁺ levels and indirectly promoted an increase in Ca²⁺ levels
by inducing an elevation in 20E levels. Furthermore, increased Ca2+ levels
inhibited the expression of Ftz-f1, leading to abnormal pupation. Our
study reveals for the first time the sublethal effects of CAP mediated by
the Ca2+-Ftz-f1 axis. The findings herein provide a reference for
evaluating the safety of environmental residues of amide pesticides on
insects.