Use of protease inhibitory gold nanoparticles as a compatibility enhancer for Bt and deltamethrin: A novel approach for pest control

Pesticide resistance is one of the most common problems, which encourage use of variety of chemical pesticides in larger quantities. Though the use of biopesticide has been advocated as an optional and ecofriendly pest control measure, it is not yet proved to be a full proof strategy for the same. To address this issue, it is important to design a new strategy which may involve combination of chemical and biopesticide. However compatibility of chemical and biopesticide is the major hurdle. Use of Bacillus thuringiensis (Bt) protein as biopesticide has been proved successful approach for vector control As like chemical pesticides, resistance to Bt proteins have also been reported. Out of the different mechanisms of insect resistance to Bt toxins, expression of high gut proteases is one major mechanism s, which leads to degradation of Bt toxins. Similar mechanism was also reported for deltamethrin resistance in mosquitoes. Here combinational strategy of Bt and deltamethrin was evaluated to check its efficacy for pest control. Although the combination was found to be effective, the compatibility experiments showed degradation of deltamethrin by Bt proteases. Hence to stabilize this complex the novel strategy was employed which involve use of combined preparations of Bt + gold nano particles (GNP) + deltamethrin mixture.