Abstract The use of botanical insecticides is a tactic that can be highly useful for the management of Helicoverpa armigera populations in the field. However, most botanical insecticides are produced using primarily macerated leaves. The problem with this process is that all components of the leaves are present in the extract, and not just the plant defence chemicals. Therefore, the objective of this research was to evaluate the feeding deterrence of a tagitinin C-rich leaf rinse extract (TagCE) obtained from Tithonia diversifolia (which concentrates mainly the plant defence substances) towards H. armigera larvae. The RP-HPLC-PDA analytical method allowed the identification and quantification of the major constituent TagCE, showing that this compound is suitable to be considered as its chemical marker. Regarding biological activity, we observed high insect mortality, with up to 80%, and high antifeedant activity for H. armigera larvae for all host plant species treated with T. diversifolia extract. These results open up the possibility to use T. diversifolia extract as a potential botanical insecticide, mainly against plant-defoliating Lepidoptera.

中文翻译：

---

Tithonia diversifolia tagitinin C 富集提取物对棉铃虫的摄食威慑作用

摘要 使用植物性杀虫剂是一种对田间棉铃虫种群管理非常有用的策略。然而，大多数植物杀虫剂主要使用浸渍的叶子生产。这个过程的问题是叶子的所有成分都存在于提取物中，而不仅仅是植物防御化学物质。因此，本研究的目的是评估从 Tithonia diversifolia（主要集中植物防御物质）中获得的富含 tagitinin C 的叶子冲洗提取物 (TagCE) 对棉铃虫幼虫的摄食威慑作用。RP-HPLC-PDA 分析方法允许对主要成分 TagCE 进行鉴定和定量，表明该化合物适合作为其化学标记物。关于生物活性，我们观察到高昆虫死亡率，高达 80%，并且对所有用 T. diversifolia 提取物处理的寄主植物物种的棉铃虫幼虫具有高拒食活性。这些结果开辟了使用 T. diversifolia 提取物作为潜在的植物杀虫剂的可能性，主要针对植物脱叶的鳞翅目。