Impact of insecticide treatments on Ostrinia nubilalis (Hübner) (Lepidoptera: Crambidae) and their influence on the mycotoxin contamination of maize kernels

Abstract

European corn borer (ECB), Ostrinia nubilalis (Hübner), is the main maize pest in Central and Southern Europe and promotes the infection of maize with Fusarium spp., which produce mycotoxins. The objective of this study was to determine the effect of insecticide treatments on ECB damage, Fusarium infection and mycotoxin contamination. The field experiments were performed from 2000 to 2006 in three locations in north-western Italy. At harvest, ears were rated for the incidence and severity of ECB damage and Fusarium ear rot symptoms, and the harvested kernels were analysed for fumonisins and zearalenone. In all the years except 2003, the chemical treatment had a significant effect on ECB incidence and severity. The ear damage was reduced, on average, by 44.1%. Fusarium ear rot and fumonisin contamination were affected by ECB control. The occurrence of the mycotoxin was significantly reduced, on average by 68%. The differences between the treatments were less clear in the year with highest ECB pressure. No significant difference was observed between the different insecticide classes. No relations were detected between the ECB activity and the occurrence of zearalenone. This research indicates that the production of kernels with low fumonisin content may be enhanced by an insecticide treatment against the second ECB generation.