Can we have it all? Controlling pests, maintaining tree health, and conserving beneficials in managed landscapes

Native trees provide critical ecosystem services in managed urban landscapes. In particular, native trees are important refugia for beneficial insects in managed settings. Despite widespread support for and implementation of native tree planting programs in urban areas across the country, the value of native trees in these settings is often diminished by stressful planting conditions and damaging outbreaks of insect pests. Controlling these pests is important for maintaining tree health and aesthetic value, but traditional management tactics such as insecticide use limit a tree’s ability to support beneficial insects. Therefore, it is critical to develop novel management tactics that help us get the most from native tree plantings by aligning the goals of controlling pests, maintaining tree health, and conserving beneficial insects. Here, we use Tuliptree (Liriodendron tulipifera), a common and ecologically important landscape tree, to explore the role of planting conditions in triggering outbreaks of two key pests: tuliptree aphid (Illinoia liriodendri) and tuliptree scale (Toumeyella liriodendri). We will also explore the role of pest outbreaks in mediating tuliptree responses to stressful planting conditions as well as its ability to conserve beneficial insects in managed settings. This research will identify impediments to insect conservation and ecosystem service delivery by native urban trees and will result in strategies to overcome these impediments in the form of novel design recommendations for managed urban landscapes.