Role of the European corn borer (Ostrinia nubilalis) on contamination of maize with 13 Fusarium mycotoxins

The European corn borer (ECB) plays an important role in promoting Fusarium verticillioides infections and in the consequent fumonisin contamination in maize grain in temperate areas. The objective of this study was to evaluate whether the ECB feeding activity could also affect the occurrence of emerging mycotoxins in maize kernels. During the 2008-10 period, natural infestation of the insect was compared, in field research, with the protection of infestation, which was obtained by using an entomological net. The ears collected in the protected plots were free from ECB attack, while those subject to natural insect attacks showed a damage severity that varied from 10% to 25%. The maize samples were analysed by means of an LC-MS/MS-based multi-mycotoxin method, which led to the detection of various metabolites: fumonisins (FUMs), fusaproliferin (FUS), moniliformin (MON), bikaverin (BIK), beauvericin (BEA), fusaric acid (FA), equisetin (EQU), deoxynivalenol (DON), deoxynivalenol-3-glucoside (DON-3-G), zearalenone (ZEA), culmorin (CULM), aurofusarin (AUR) and butenolide (BUT). The occurrence of mycotoxins produced by Fusarium spp. of Liseola section was affected significantly by the ECB feeding activity. The presence of ECB injuries increased the FUMs from 995 to 4694 mu gkg(-1), FUS from 17 to 1089 mu gkg(-1), MON from 22 to 673 mu gkg(-1), BIK from 58 to 377 mu gkg(-1), BEA from 6 to 177 mu gkg(-1), and FA from 21 to 379 mu gkg(-1). EQU, produced by F. equiseti section Gibbosum, was also increased by the ECB activity, by 1-30 mu gkg(-1) on average. Instead, the content of mycotoxins produced by Fusarium spp. of Discolor and Roseum sections was not significantly affected by ECB activity. As for FUMs, the application of a strategy that can reduce ECB damage could also be the most effective solution to minimise the other mycotoxins produced by Fusarium spp. of Liseola section.