Dr. Stacy Philpott, from the Environmental Studies Department at U.C. Santa Cruz, and Dr. Helda Morales, from the Agroecology Group at El Colegio de la Frontera Sur, received a 2014 UC MEXUS-CONACYT Collaborative Grant for their research and education project examining the potential of urban gardens to support biodiversity and conservation biological control of crop pests. Their research in 12 urban gardens in Chiapas and 18 urban gardens in the California Central Coast looked at the importance of local management characteristics (e.g., crop and ornamental plant selection, presence of trees, ground cover characteristics) and landscape surroundings (e.g. amount of natural habitat and concrete in the area around the garden) for enhancing biological control of crop pests in urban gardens.
Working with multi-cultural teams of students, faculty and staff from the U.S., Mexico, Guatemala, Colombia, Venezuela, and Spain, Philpott and Morales sampled gardens for natural enemies of various agricultural pests such as ladybeetles and parasitoid wasps and used decoy pest removal experiments to examine biological control methods. They found that ladybeetles were more diverse in gardens with less concrete and less natural habitat, and thrived in areas with grass1. Parasitoid wasps were more common in gardens with higher vegetation complexity (more crop species, taller plants, more species of trees and shrubs) but declined in gardens surrounded by more concrete
. Predators removed between 40-90% of pests in just 24 hours, and pest control services varied with local and landscape features of the habitats3. Pilot data from this project allowed Philpott to apply for and receive a USDA grant investigating pollination, pest control, and water conservation services in urban gardens in the U.S. Morales and her students continue to do social and ecological research in the urban gardens in Chiapas. The project also involved monthly videoconferences and workshops to forge partnerships between students and to educate and train the student participants in international, intercultural, collaborative experiences.
1 Egerer ME, Bichier P, Philpott SM. (2016) Landscape and local habitat correlates of lady beetle abundance and species richness in urban agriculture. Annals of the Entomological Society of America. doi: 10.1093/aesa/saw063
2 Burks J, Philpott SM. (2017) Local and landscape drivers of parasitoid abundance, richness, and composition in urban gardens. Environmental Entomology, in press
3 Philpott SM, Bichier P. (2017) Local and landscape drivers of predation services in urban gardens. Ecological Applications, in press