RNA interference (RNAi) of vital insect genes is a potential tool for targeted pest management. However, the selection of the right target genes and its dsRNA delivery method is also a challenge because the RNAi efficacy is known to vary among insect species. Fall Armyworm (FAW; Spodoptera frugiperda) is a polyphagous generalist insect pest that can feed on more than 100 plant species, with a strong preference for maize. In the present study, we evaluated the RNAi efficiency of three vital genes coding for Coatomer Subunit alpha (COPIα), Coatomer Subunit beta (COPIβ) and Glutathione-S-transferase U1 (GSTU1) as potential targets for managing FAW. Real-time PCR analysis showed that the target genes' expression level reduced to 75–80% in FAW larvae, after their continuous oral delivery through diet for 8 days. It also caused significant mortality in larvae (40–50%) and pupae (40–62%), and resulted in deformed intermediates (28–38%) and adults (25–40%). It also affected reproduction as evidenced by an approximately 50% reduction in oviposition. Moreover, exogenous application of dsRNA in maize leaves resulted in significant feeding deterrence by FAW larvae, which enhanced the frequency of cannibalism. The impact of target genes’ dsRNA on the biology and behaviour of FAW suggests their insecticidal potential. Thus, the current study reveals the novel target genes and their utility in RNA based pesticides for sustainable management of FAW.

中文翻译：

---

鉴定 RNAi 介导的害虫草地贪夜蛾 （Spodoptera frugiperda， JE Smith） 管理的新靶基因


重要昆虫基因的 RNA 干扰 （RNAi） 是针对性害虫管理的潜在工具。然而，选择正确的靶基因及其 dsRNA 递送方法也是一个挑战，因为已知 RNAi 功效因昆虫物种而异。草地贪夜蛾 （FAW;草地贪夜蛾）是一种多食性多面性害虫，可以以 100 多种植物为食，对玉米有强烈的偏好。在本研究中，我们评估了编码 Coatomer 亚基 alpha （COPIα） 、Coatomer 亚基 β （COPIβ） 和谷胱甘肽-S-转移酶 U1 （GSTU1） 的三个重要基因的 RNAi 效率，作为管理 FAW 的潜在靶点。实时 PCR 分析显示，通过饮食连续经口分娩 8 天后，FAW 幼虫中靶基因的表达水平降低到 75-80%。它还导致幼虫 （40-50%） 和蛹 （40-62%） 的大量死亡，并导致中间体 （28-38%） 和成虫 （25-40%） 变形。它还影响了繁殖，产卵量减少约 50% 证明了这一点。此外，在玉米叶片中外源施用 dsRNA 导致 FAW 幼虫显着的摄食威慑力，这增加了同类相食的频率。靶基因的 dsRNA 对 FAW 生物学和行为的影响表明它们的杀虫潜力。因此，目前的研究揭示了新的靶基因及其在基于 RNA 的农药中对 FAW 可持续管理的效用。