The European corn borer (ECB), Ostrinia nubilalis Hb., is a major pest of maize in central Europe and promotes the infection of maize with Fusarium spp. In this study, transgenic Bt maize hybrids were compared with their isogenic counterparts, and with commercial hybrids from the recommended list with regard to their level of ECB resistance and their concentration of deoxynivalenol (DON), its 15‐acetyl (15‐A‐DON) and 3‐acetyl (3‐A‐DON) derivatives, nivalenol (NIV), fusarenon‐X (FUS‐X), fumonisins (FUM), and zearalenon (ZEN) in harvested grains. The field experiments were performed in Germany at four locations in 1999 and at five locations in 2000. Transgenic Bt hybrids showed significantly lower means than their corresponding isogenic counterparts and than commercial hybrids for all resistance traits: damage rating of stalks, number of larvae per plant, number of larvae per ear, and percentage of damaged plants or ears under infestation. Among all mycotoxins analysed, DON consistently showed the highest concentration across all year × location combinations. Mycotoxin concentrations varied significantly between locations, years and genotypes, whereas mycotoxin concentrations were not significantly different between infested and protected plots. Associations between ECB resistance traits and mycotoxin concentrations were not consistent across years. It is concluded that under central European conditions, the use of Bt maize hybrids will only slightly reduce the contamination of maize kernels with mycotoxins produced by Fusarium spp.

The European corn borer (ECB), Ostrinia nubilalis (Hübner), is a major pest of maize (Zea mays L.) in Central Europe. In order to compare transgenic Bt maize hybrids with their non‐transgenic counterparts and commercial hybrids, field trials and a laboratory bioassay were conducted. The field experiments were performed at four locations with natural and manual infestation of ECB larvae in 1998 and 1999. Transgenic Bt hybrids showed significantly lower means than their corresponding non‐transgenic counterparts and commercial hybrids for all resistance traits (damage rating of stalks, number of larvae per plant, and percentage of damaged plants or ears under infestation). Bt hybrids containing the CryIA(b) gene under the control of green tissue and pollen‐specific promoters (event 176) showed a significantly higher percentage of damaged ears than Bt hybrids carrying the CryIA(b) gene under the control of a constitutive promoter (Mon810). Bt and non‐Bt hybrids showed no significant differences for all agronomic traits, except for plant height under insecticide protection and grain yield reduction under infestation, whereas Bt hybrids had significantly lower means than their non‐transgenic counterparts and other commercial hybrids. All resistance traits were significantly correlated with grain yield reduction. The laboratory bioassay confirmed the level of antibiosis of Bt hybrids against neonate ECB larvae. Bt hybrids showed the highest level of ECB resistance and therefore are an attractive method of preventing ECB damage within an integrated pest‐management system.

The European corn borer (ECB), Ostrinia nubilalis Hb., is a major pest of maize in Central Europe and is suspected to promote infection of maize with Fusarium species. The objectives of this study were to (1) determine moniliformin (MON) concentration in early maturing European Bt maize hybrids, their isogenic counterparts, commercial cultivars and experimental hybrids, (2) evaluate the association between MON concentration and ECB resistance and (3) correlate MON concentration with concentrations of other mycotoxins determined from the same plant materials. The field experiments were performed at five locations in Germany. MON concentration was significantly higher with manual infestation of ECB larvae (296 μg/kg) than under insecticide protection (66 μg/kg). Bt hybrids showed significantly lower MON concentrations and higher grain yields under manual ECB infestation than their corresponding isogenic counterparts, as well as commercial and experimental hybrids. All ECB resistance traits and grain yield under ECB infestation were significantly correlated with MON concentration. Correlations between concentrations of MON and other Fusarium mycotoxins were not significant. The use of Bt maize hybrids or insecticides to control ECB reduces the contamination of maize grains with MON in Central Europe. The presence of resistance genes against Fusarium species in the current elite maize germplasm was indicated by ECB susceptible non‐Bt hybrids with low‐MON concentrations.

Stalk and ear rots caused by Fusarium subspecies are often related to mycotoxin accumulation in maize (Zea mays L.) kernels. Various mycotoxicoses in livestock and humans are triggered by the consumption of these toxins. The European corn borer (Ostrinia nubilalis Hübner) reportedly promotes the infection by Fusarium spp. The objectives of our study were to (i) evaluate the concentration of deoxinivalenol (DON), 3‐acetyl‐deoxynivalenol (3‐A‐DON), 15‐acetyl‐deoxynivalenol (15‐A‐DON), fumonisin (FUM), fusarenon‐X (FUS‐X), moniliformin (MON), and nivalenol (NIV) in kernels; (ii) determine the level of European corn borer (ECB) resistance; and (iii) investigate the association between the concentration of mycotoxins and ECB resistance. The study used early maturing European Bt (Bacillus thuringiensis) cultivars, their isogenic counterparts, and commercial hybrids. The field experiments were conducted at three locations in Germany. The mycotoxins most prevalent were DON, FUM, and MON. Plots infested by and protected from ECB differed significantly for DON and FUM concentrations. In addition, significant differences were found for concentrations of FUM between isogenic Bt and non‐Bt hybrids. The two Bt events—Bt176 and Mon810—were also significantly different for FUM concentrations. Not all mycotoxins were related to ECB damage. Insect management and, therefore, the use of Bt cultivars may be a short‐term solution to minimize toxins in kernels.