Leaf ties assemble diverse arthropod communities

Through the simple act of tying leaves together with silk, shelter-building caterpillars create diverse micro-ecosystems that provide food, shelter, and a nursery to many different organisms at multiple trophic levels. The potential of these ecosystem engineers to create novel habitats and alter community dynamics implies that leaf ties play a critical role in the creation and maintenance of biodiversity. Caterpillars that create leaf ties do so in their own interest, but other caterpillars and arthropods often utilize that same leaf tie in tandem or sequentially. These shelters can persist for an entire growing season, meaning that several generations of multiple species may inhabit the same leaf tie, interacting directly and indirectly through time. Because they create novel micro-habitats, leaf tiers create historical contingency whereby the initial conditions of leaf ties can have significant effects on the assemblage of the entire community. While we know that leaf ties create favorable abiotic environments that facilitate arthropod abundance and biodiversity, we know little about the complex processes and behaviors that influence the assembly of arthropod communities within leaf ties. I am investigating the cues that govern leaf tie colonization via two distinct routes: mobile transient arthropods, and adult females laying eggs inside ties. Preliminary data show that the community of mobile secondary inhabitants differs from that of oviposited individuals, and that caterpillar occupancy is an important cue for secondary colonists.