Resumen
- The potato tuber moth Tecia solanivora is an invasive species threatening potato crops and stored tubers. Previous studies have shown that South American populations of this species have evolved insecticide resistance to major classes of insecticides (i.e., pyrethroids, carbamates and organophosphates). Therefore, testing for other methods of pest control is of increasing importance. In this study, we evaluated the toxic effect of chlorantraniliprole against early immature stages of T. solanivora. We carried out a concentration–mortality bioassay using eggs. Subsequently, we subjected eggs to several insecticide application scenarios and evaluated hatching success, larvae activity and overall mortality of immature stages. Additionally, we analysed the hatching behaviour of larvae when the eggs were treated with chlorantraniliprole. After the concentration–mortality bioassay, we calculated an LC50 of 298.6 ppm, yet the mortality did not occur during the egg-phase, but rather the neonate larvae experienced the toxic effects of chlorantraniliprole. In the subsequent exposure-mode bioassay, the hatching success was overall high in all treatments, and larvae mortality reached 100% regardless of exposure mode. Consequently, larvae activity was severely reduced when in contact with the insecticide. Furthermore, when eggs are subjected to such LC50 dose, larvae manage to break through the chorion, but after releasing the legs, each hatching stages takes longer than the previous. Our results highlight the potential use of chlorantraniliprole for the control of T. solanivora in stored potato tubers. Additionally, chlorantraniliprole appears to be a promising alternative for the control of T. solanivora populations resistant to neurotoxic insecticides.