The combination of a companion plant with a cultivated plant is considered an interesting strategy to reduce pest pressure and, hence, the use of pesticides. Although several plants from the Alliaceae and Lamiaceae families are known to be efficient companion plants against aphid pests, only a few plants of the Geraniaceae family have been studied so far. The aim of this work was to investigate the potential effects of Geranium macrorrhizum as a companion plant on the colonization of sweet pepper (Capsicum annuum, Solanaceae) by the green peach aphid (Myzus persicae). Aphid’s orientation behavior, probing behavior and life history traits were assessed on sweet pepper using a host choice preference setup, Electrical Penetration Graph technique and clip-cage laboratory bioassays, respectively. The potential disturbance through mechanical stimulation of geranium leaves was also assessed. The composition of VOCs from G. macrorrhizum leaves was analyzed using SPME technic followed by GC–MS. This study revealed that G. macrorrhizum as a companion plant was intrinsically repellent but not enough to completely mask the attractive odor of the sweet pepper host plant. Moreover, G. macrorrhizum negatively impacted the probing behavior, fecundity and survival rate of M. persicae on sweet pepper. The effects were exacerbated when G. macrorrhizum leaves were mechanically stimulated. This could be due to the greater amount of the main VOCs germacrone and β-elemenone emitted by G. macrorrhizum following mechanical stimulation. Our results bring new insights into the use of novel companion plants to regulate aphid pest populations.

将伴生植物与栽培植物相结合被认为是减少害虫压力并因此减少杀虫剂使用的有趣策略。虽然已知葱科和唇形科的几种植物是对抗蚜虫害虫的有效伴侣植物，但迄今为止只有少数天竺葵科植物被研究过。这项工作的目的是研究天竺葵作为伴生植物对桃蚜 ( Myzus persicae )定殖甜椒 ( Capsicum annuum , Solanaceae) 的潜在影响。）。分别使用宿主选择偏好设置、电穿透图技术和夹笼实验室生物测定法对甜椒的蚜虫定向行为、探测行为和生活史特征进行了评估。还评估了通过机械刺激天竺葵叶子的潜在干扰。使用 SPME 技术和 GC-MS 分析来自G. macrorrhizum叶子的 VOC 的组成。这项研究表明，作为伴生植物的G. macrorrhizum本质上具有驱虫性，但不足以完全掩盖甜椒寄主植物的诱人气味。此外，G. macrorrhizum对M. persicae的探测行为、繁殖力和存活率有负面影响。在甜椒上。当机械刺激G. macrorrhizum叶子时，效果会加剧。这可能是由于在机械刺激后，大根茎释放的主要 VOCsgermacrone 和 β-elemenone 的量更大。我们的研究结果为使用新型伴生植物调节蚜虫种群带来了新的见解。