Top-down and bottom-up controls on an herbivore on a native and introduced plant in a tropical agricultural landscape.

The recent introduction in a tropical agricultural environment of a weedy open-habitat plant () and subsequent host range expansion of a common forest-edge butterfly () onto that plant provides an opportunity to examine reconfiguration of tritrophic networks in human-impacted landscapes. The objectives of this study were (1) determine if the caterpillars on the exotic host are more or less limited by plant defenses (bottom-up forces) and if they experience enemy release (decrease of top-down pressure) and (2) define how anthropic open pasture habitat influences the herbivore's tritrophic niche. Field and laboratory monitoring of larval survival and performance on a native () host plant and the exotic () host plant were conducted in the Mindo Valley, Ecuador.