Silicon can increase the natural defence of plants against stresses including herbivorous insects. Silicon dioxide (SiO₂) is one of the forms of silicon, and despite its wide use in the industrial sector, its use in agriculture is still poorly adopted. The aim of this study was to evaluate the effectiveness of foliar application of SiO₂ in inducing defence against Spodoptera frugiperda in soybean. The experiments were conducted in a completely randomised design with four treatments (0%, 1%, 2.5%, and 5% of SiO₂). The effect on cannibalism, biological parameters (mortality, duration of the larval stage, duration of the pupal stage and pupal weight) and wear on the mandible of S. frugiperda were evaluated. The foliar silicon content was also determined. The supply of SiO₂ prolonged the duration of the larval and pupal stages of the S. frugiperda by 0.56 and 0.17 days for each 1% of SiO₂ applied, respectively. The use of SiO₂ at 5% increased the mortality rate of caterpillars in the larval stage by approximately 25%. There was no effect of SiO₂ application on cannibalism and weight of S. frugiperda pupae. There was wear on the caterpillars' jaws in the third and fourth instar at the highest SiO₂ concentration. The application of SiO₂ promoted greater accumulation of silicon in soybean leaves. It is concluded that the foliar application of SiO₂ affects the biological performance of S. frugiperda through the induction of defence in the soybean crop and presents itself as a promising strategy in integrated pest management programmes.

中文翻译：

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二氧化硅诱导大豆对抗草地贪夜蛾的防御作用

硅可以增强植物对包括食草昆虫在内的胁迫的天然防御能力。二氧化硅（SiO ₂）是硅的一种形式，尽管其在工业领域得到广泛应用，但其在农业中的应用仍然很少。本研究的目的是评估叶面喷施 SiO ₂在诱导大豆防御草地贪夜蛾中的有效性。实验采用完全随机设计，采用四种处理（0%、1%、2.5% 和 5% SiO ₂）。评估了对同类相食、生物学参数（死亡率、幼虫阶段持续时间、蛹阶段持续时间和蛹重量）以及对草地贪夜蛾下颌骨磨损的影响。还测定了叶面硅含量。每施用1％的SiO _{2 ，​​SiO 2}的供应使草地贪夜蛾幼虫期和蛹期的持续时间分别延长0.56天和0.17天。使用5%的SiO ₂使幼虫阶段毛毛虫的死亡率增加约25%。_{施用SiO 2对}草地贪夜蛾蛹的同类相食和体重没有影响。_{在最高SiO 2}浓度下，第三龄和第四龄毛虫的下颌出现磨损。施用SiO ₂促进了大豆叶片中硅的积累。结论是，叶面施用 SiO ₂通过诱导大豆作物的防御来影响草地贪夜蛾的生物学性能，并使其成为综合害虫管理计划中的一种有前景的策略。