Effects of invasive exotic plants on plant communities are often profound, but interactions with higher trophic levels are less evident. Postulated effects of invasive plants on arthropods include increased abundances of herbivores through refuge and improved microclimate, facilitation of other exotic species, and altered arthropod diversity. We examined the impact on the arthropod community by Lespedeza cuneata, an exotic legume with dense, chemically defended foliage, by comparing arthropod numbers in unmanipulated 1-m² plots with L. cuneata shoots (= control) to arthropod numbers in plots from which shoots of L. cuneata were removed. Lespedeza cuneata removal produced no overall effect on arthropod abundance, but an invasive herbivore, Popillia japonica (Japanese Beetle), was twice as abundant in plots with L. cuneata. Lespedeza cuneata removal increased arthropod evenness in May then decreased it through the summer. In a second experiment we quantified chewing herbivory by placing individual potted plants from five native prairie species and L. cuneata within these same removal/no removal plots for 4 weeks. Removal of L. cuneata shoots from plots did not significantly affect herbivory of tagged leaves from the native species. However, entire L. cuneata leaves or plants disappeared more frequently regardless of plot treatment. Invasion by this exotic legume is likely due to direct effects on native plants, but indirect effects through facilitation of an exotic herbivore could contribute to its success in some areas.

外来入侵植物对植物群落的影响通常是深远的，但与较高营养水平的相互作用不太明显。入侵植物对节肢动物的假设影响包括通过避难所增加食草动物的丰度和改善小气候、促进其他外来物种的发展以及改变节肢动物的多样性。我们通过比较未处理的 1-m ²地块中的节肢动物数量与L. cuneata枝条（= 对照）与枝条生长的地块中的节肢动物数量，研究了Lespedeza cuneata对节肢动物群落的影响，Lespedeza cuneata是一种具有密集、化学防护叶子的外来豆科植物的L.藤被拆除。胡枝子去除对节肢动物丰度没有整体影响，但入侵草食动物Popillia japonica（日本甲虫）在L. cuneata 的地块中的数量是其两倍。Lespedeza cuneata 的去除在 5 月增加了节肢动物的均匀度，然后在整个夏季减少了。在第二个实验中，我们通过将来自五个本地草原物种和L. cuneata 的单个盆栽植物放置在这些相同的去除/不去除地块中 4 周来量化咀嚼食草动物。从地块中去除L. cuneata枝条不会显着影响来自本地物种的标记叶子的食草性。然而，整个L. cuneata无论地块处理如何，叶子或植物都更频繁地消失。这种外来豆科植物的入侵可能是由于对本地植物的直接影响，但通过促进外来食草动物的间接影响可能有助于其在某些地区的成功。