Variability of intraspecific host plant quality for phytophagous insects may have consequences on the structure and functioning of associated food webs. The quality of host plants can affect aphids fitness, influencing their life history traits and altering the nutritional resources available to higher trophic levels, potentially affecting the development of solitary parasitoids. Here, we assessed the potential bottom-up effects of intraspecific variability among three cultivars (Gala, Ariane, and Greensleeves) of the domesticated apple tree (Malus domestica) with putative resistance towards the rosy apple aphid (Dysaphis plantaginea) on the aphid’s performance, and its cascading effects on the parasitoid Ephedrus cerasicola. We measured aphids pre-reproductive period, lipid, and water contents, and recorded their feeding behavior using the electropenetrography technique. Parasitoid developmental duration, sex ratio, hind tibia size, and female egg load were measured and used to evaluate E. cerasicola performance according to the cultivar on which their aphid hosts had been reared. Only the development time of parasitoids was found to be longer on Ariane and Green Sleeves cultivars than on the Gala cultivar. Aphid-feeding behavior variables related to phloem consumption were negatively impacted on apple tree cultivars on which the development time of parasitoids had been reduced. We discuss ways in which cultivar quality can be an important component of tritrophic interactions: the resistant Ariane and Green Sleeves cultivars negatively impacted the aphids but appeared to have limited bottom-up effects on the parasitoids.

植食性昆虫种内寄主植物质量的变异可能会对相关食物网的结构和功能产生影响。寄主植物的质量会影响蚜虫的适应性，影响其生活史特征并改变更高营养水平可用的营养资源，从而可能影响独居寄生蜂的发育。在这里，我们评估了对红苹果蚜虫（ Dysaphis plantaginea）具有假定抗性的驯化苹果树（ Malus Domestica）的三个品种（Gala、Ariane和Greensleeves）之间种内变异对蚜虫性能的潜在自下而上的影响，及其对寄生蜂Ephedrus cerasicola的级联效应。我们测量了蚜虫的繁殖前期、脂质和水分含量，并使用渗透电图技术记录了它们的摄食行为。测量寄生蜂发育持续时间、性别比例、后胫骨大小和雌性卵负载，并根据饲养蚜虫寄主的品种来评估小叶小蠹的性能。只是发现阿丽亚娜和绿袖品种的寄生蜂发育时间比嘎拉品种长。与韧皮部消耗相关的蚜虫取食行为变量对寄生蜂发育时间缩短的苹果树品种产生负面影响。我们讨论了品种质量如何成为三营养相互作用的重要组成部分：抗性阿丽亚娜和绿袖品种对蚜虫产生了负面影响，但似乎对寄生蜂具有有限的自下而上的影响。