Development and Perfection of Marine-Based Insecticide Biofilm for Pea Seed Protection: Experimental and Computational Approaches

This work aims to develop an insecticidal biofilm based on Calothrixin A, collagen, and chitosan for the protection of pea seeds. The main objective is to improve the ingredient concentrations maximizing the insecticidal activity of the biofilm and to study the desorption of Calothrixin A according to the diffusion parameters. Eight biofilm formulations were prepared with different concentrations of the components and tested on <i>Sitona lineatus</i> and <i>Bruchus pisorum</i>. The results show that a high concentration of Calothrixin A tended to increase insecticidal activity, although this increase was not always significant, while a higher concentration of collagen and chitosan reduced insecticidal activity, probably by limiting the diffusion of the active ingredient. The prediction models for insecticidal activity showed that the interaction of the factors had no significant impact on the responses, but the model for <i>Sitona lineatus</i> presented better accuracy. The diffusion tests revealed that the CB3C-5 biofilm, with high diffusion parameters, correlated with insecticidal activity. The characterization of the CB3C-5 biofilm showed adequate physical, mechanical, thermal, and structural properties for agricultural seed storage application. Moreover, the computational approach showed that Calothrixin A interacts more efficiently with the OR5-Orco complex than with the small OBP, disrupting the olfactory detection of insects. This mechanism highlights the targeting of the olfactory complex as a potential strategy to control insect pests. This research contributes to the understanding of the role of marine-based biofilms for seed protection and opens perspectives for the development of ecological solutions against insect pests, particularly in the field of sustainable agriculture.