Role of Sesamia nonagrioides and Ostrinia nubilalis as Vectors of Fusarium spp. and Contribution of Corn Borer-Resistant Bt Maize to Mycotoxin Reduction.

María Arias-Martín,Belén Patiño,Gema P Farinós,Miriam Haidukowski

doi:10.3390/toxins13110780

Abstract

Maize expressing Cry1Ab insecticidal toxin (Bt maize) is an effective method to control Sesamia nonagrioides and Ostrinia nubilalis, the most damaging corn borers of southern Europe. In this area, maize is prone to Fusarium infections, which can produce mycotoxins that pose a serious risk to human and animal health, causing significant economic losses in the agrifood industry. To investigate the influence of corn borer damage on the presence of Fusarium species and their mycotoxins, Bt maize ears and insect-damaged ears of non-Bt maize were collected from commercial fields in three Bt maize growing areas in Spain, and differences in contamination were assessed. Additionally, larvae of both borer species were collected to evaluate their role as vectors of these molds. Non-Bt maize ears showed significantly higher presence of F. verticillioides, F. proliferatum, and F. subglutinans than Bt maize ears. For the first time, Fusarium species have been isolated from larvae of the two species. The most frequently found mycotoxins in ears were fumonisins, with non-Bt ears being significantly more contaminated than those of Bt maize. High levels of fumonisins were shown to correlate with the occurrence of corn borers in the ear and the presence of F. verticillioides and F. proliferatum.

Highlights

Maize (Zea mays L.) is one of the most important agricultural crops worldwide, being fundamental in the production chains of food and feed
Corn borer damage to the plant has been found to be an important driver of mycotoxigenic fungal growth and mycotoxin production [3], so the use of Cry1Ab-expressing Bt maize could lead to a reduction of both problems
Bt maize is mainly distributed in three areas of this country (the northeast (Ebro Valley), center and southwest (Andalucia)), where this study was carried out, and which are characterized by significant attacks by S. nonagrioides, O. nubilalis, or both corn borers [37,38]

Summary

Introduction

Maize (Zea mays L.) is one of the most important agricultural crops worldwide, being fundamental in the production chains of food and feed. Mycotoxins can be produced both before and after harvest, including during storage and processing [3], and the most usual way in which they enter the food chain is through contaminated crops, mainly cereals, which are intended for food and feed. In terms of food safety, they are the most important risk associated with cereal consumption [4]. Even though in most cases the concentrations of mycotoxins in the feed supply chain are low enough to ensure compliance with the limits set by the European Union (EU), multi-mycotoxin contamination can increase the risk of mycotoxicosis in cattle due to additive/synergistic interactions [8,9,10]

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