Field trials based on manual infestation of the Asian corn borer (ACB) (Ostrinia furnacalis [Guenée]) and Fusarium verticillioides (Nirenberg) atomization were conducted on four maize hybrids to investigate the relationship between ACB infestation and F. verticillioides infection, yield loss, and fumonisin contamination in maize. Analysis of fumonisins B1 and B2 was carried out using an LC-MS/MS system. In this study, manual ACB infestation significantly promoted F. verticillioides infection (both symptomatic and symptomless) and grain fumonisin levels. Ear rot incidence and severity, symptomless kernel infection, and fumonisin contamination were significantly correlated to each other and to ACB damage severity. Manual ACB infestation increased fumonisin levels from 580 to 4,418 µg/kg in 2018; 6,059 to 10,681 µg/kg in 2019 spring-sown maize (2019A); and 2,042 to 5,060 µg/kg in 2019 summer-sown maize (2019B), with the threshold of the European Union (EU) being 4,000 µg/kg. The threshold was exceeded in spring of 2019 in untreated controls. Regarding yield, significant negative correlation between ACB damage and ear weight was observed in three seasons. These results indicated that ACB infestation can lead to severe quality degradation and yield loss of maize. Kernel fumonisin levels may exceed the concentration threshold of the EU in certain conditions, threatening the health of livestock and humans. Measures should be taken to reduce ACB infestation to ensure food and feed security.
Keywords: Fusarium verticillioides; Ostrinia furnacalis; fumonisins; maize ear rot; symptomless infection; yield loss.