Betty Benrey Seminar

The Mesoamerican milpa, an intercropping system of maize, beans, and squash, exemplifies how plant diversity enhances natural pest control and agroecosystem resilience. Through field and laboratory experiments in Oaxaca, Mexico, we show that plant diversity fosters more diverse and abundant communities of natural enemies and herbivores aboveground, while also supporting richer and more functional microbial communities belowground. These interactions contribute to associational resistance (AR), where traits like extrafloral nectar (EFN) production in beans attract beneficial insects that reduce herbivores on neighboring maize. Moreover, herbivore-induced volatiles (HIPVs) from maize trigger EFN secretion in beans, revealing synergistic interactions among companion plants. Together, the diversity of the milpa creates a web of above- and belowground interactions that sustain pest suppression, soil health, and crop productivity — offering valuable insights for designing more sustainable and resilient agricultural systems.