Human management in cities and suburbs: Challenges and opportunities for insect conservation

Insect herbivores require a variety of habitats across their life cycle, with behavior often mediating transitions between life stages or habitats. Human management strongly alters urban habitats, yet herbivore behavior is rarely examined in cities. Here we review the existing knowledge connecting human management to several key behaviors: host finding, feeding, egg placement and pupation location, and antipredator defense through a series of research vignettes. We emphasize that unapparent portions of the life cycle, such as the habitat of the overwintering stage, may influence if urbanized areas act as population sources or sinks. Here, management of the soil surface and aboveground biomass are two areas with especially pressing research gaps. Lastly, high variability in urban environments may select for more plastic behaviors or greater generalism. Human management can thus present both opportunities and challenges for the conservation of herbivorous insects in cities. This is particularly relevant because insect herbivores are the building blocks of healthy urban food webs and often perform important ecosystem services during other portions of their lifecycles.