Resistance of two maize varieties to postharvest pests: interaction with natural enemies and mycotoxin production by mold Aspergillus flavus

Abstract: Biocontrol methods are vital in agricultural management, with resistant varieties
being a prominent mechanism. Genetic resistance demonstrated by transgenic Bt maize
producing cry proteins targeting specific insect species has high control efficacy in fields.
However, understanding the complexity of resistance mechanisms is essential, especially
considering the diverse array of insects present during postharvest phases. This study aims to
assess the susceptibility of two maize varieties including its transgenic and wildtype variety to
stored product insect pests and fungal mold Aspergillus flavus. By evaluating grain damage,
insect population dynamics, and the presence of and associated mycotoxins produced by A.
flavus, the research aims towards preventive biocontrol mechanisms. Our findings indicate that transgenic maize displays robust resistance against Sitotroga cerealella but exhibits lower resistance against Sitophilus zeamais and Orizaephilus surinamensis. Furthermore, the resistance of natural enemies and A. flavus significantly influences resistance levels,
emphasizing the specificity of cry proteins in grain protection. This research contributes to
identifying key qualities influencing resistance and comprehending the underlying mechanisms crucial for enhancing stored maize biocontrol strategies.