The Effects of Urban Warming on Predators of Street Tree Pests

Urban forests provide food and shelter for a variety of wildlife. The urban heat island effect causes higher pest populations on urban trees, reducing tree vigor and health. Natural enemies such as predators and parasitoids play a crucial role in controlling arthropod pests that occur on street trees such as aphids, scale insects, and caterpillars. In this study, we investigated how urban warming affects predator abundance, community structure, and diversity. We found that spiders are by far the most abundant predatory species on street trees and identified significant spider families that could play key roles in reducing street tree pest populations. This will inform which spider families to study and conserve in street trees across the urban warming gradient.