Associational effects are a phenomenon in which herbivore damage on co-occurring plant species is influenced by neighboring plants. Mistletoes are a group of shrubs that obtain nutrients from host plants through haustoria. Despite the potential for mistletoe herbivory to be affected by associational effects with their hosts, the effects of host and mistletoe functional traits on mistletoe herbivory have been largely overlooked. This study aimed to evaluate the associational effects of host plants and the direct effects of mistletoe functional traits on mistletoe herbivory. To achieve this, we measured leaf herbivory and leaf traits of three mistletoe species (Dendrophthoe pentandra, Scurrula chingii var. yunnanensis, and Helixanthera parasitica) and their associated 11 host species during both dry and wet seasons. Our results showed that leaf herbivory of D. pentandra and S. chingii var. yunnanensis differed significantly on their respective host species, but H. parasitica did not. The relationships between mistletoe and the paired host herbivory differed between seasons, with a stronger positive relationship observed during the dry season. Furthermore, significant relationships were observed between paired leaf carbon, leaf nitrogen, and condensed tannin in mistletoes and their host plants, indicating that host plants can affect mistletoes' leaf functional traits. A group of mistletoe leaf traits provided significant predictions for leaf herbivory: leaves with higher leaf thickness and leaf total nitrogen showed higher herbivory. Overall, our study reveals that mistletoe leaf herbivory is directly affected by its leaf traits and indirectly affected by host associational effects, primarily through changes in mistletoes' leaf traits.

关联效应是一种食草动物对共生植物物种的损害受到邻近植物影响的现象。槲寄生是一类通过吸器从寄主植物获取营养的灌木。尽管槲寄生食草动物可能受到与寄主的关联效应的影响，但寄主和槲寄生功能性状对槲寄生食草动物的影响在很大程度上被忽视了。本研究旨在评估寄主植物的关联效应以及槲寄生功能性状对槲寄生草食性的直接影响。为了实现这一目标，我们测量了三种槲寄生物种（Dendrophthoe pentandra、Scurrula chingii var. yunnanensis和Helixanthera parasitica）及其相关 11 个寄主物种在旱季和雨季的叶子食草性和叶子性状。我们的结果表明，D. pentandra和S. chingii var. 是叶草食性的。yunnanensis在各自的宿主物种上存在显着差异，但H. parasitica则没有。槲寄生和配对寄主食草动物之间的关系在不同季节有所不同，在旱季观察到更强的正相关关系。此外，在槲寄生及其寄主植物中，配对叶片碳、叶片氮和缩合单宁之间观察到显着关系，表明寄主植物可以影响槲寄生的叶片功能性状。一组槲寄生叶片性状为叶片食草性提供了重要的预测：叶片厚度和叶片总氮较高的叶片表现出较高的食草性。总体而言，我们的研究表明，槲寄生叶草食性直接受到其叶子性状的影响，并间接受到寄主关联效应的影响，主要是通过槲寄生叶子性状的变化。