title: Impact of Regionally Distinct Agroecosystem Communities on the Potential for Autonomous Control of the Coffee Leaf Rust.
abstract: Recent theoretical work suggests that two ineffective control agents can provide effective biological control when coupled together. We explore the implications of this work with the system of coffee leaf rust (CLR), caused by the fungal agent Hemileiae vastatrix, and two of its natural enemies, a fungal pathogen (Lecanicillium lecanii) and a spore predator (Mycodiplosis hemileiae). Here we report on comparative surveys of the CLR and its two natural enemies in Mexico, where the CLR has been at epidemic status since 2012, and Puerto Rico, where the CLR is present but has not reached epidemic densities. We found that the densities of the two control agents per CLR lesion is higher in Puerto Rico than in Mexico, and we hypothesize that their joint presence at higher densities is contributing to the suppression of the CLR in Puerto Rico but not in Mexico. Furthermore, we found that the presence of Azteca sericeasur, a keystone ant species that occurs in Mexico but not Puerto Rico, significantly reduces the prevalence of M. hemileiae on coffee plants. Our work provides data that allows us to hypothesize that the joint presence of these two control agents may potentially provide control of the CLR and also highlights the importance of regionally specific communities within agroecosystems, and how variation in community composition may lead to varying outcomes for biological control. Additionally, this is the first report of the presence of a potentially important biological control agent, M. hemileiae, in Latin America and the Caribbean.
authors.affiliation: Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109 (zhajianf@umich.edu; jvander@umich.edu) zhajianf@umich.edu.|Present address: Natural Science Building 830 N. University Ave. Room 2081, Ann Arbor, MI 48109.
authors.forename: Zachary
authors.initials: Z
authors.lastname: Hajian-Forooshani
authors.affiliation: Departamento de Agroecología, Universidad Autónoma Chapingo, Texcoco, Mexico (irissaraeny@gmail.com).
authors.forename: Iris Saraeny
authors.initials: IS
authors.lastname: Rivera Salinas
authors.affiliation: Environmental Studies Department, University of California, Santa Cruz, CA 95064 (maesjime@ucsc.edu).
authors.forename: Estelí
authors.initials: E
authors.lastname: Jiménez-Soto
authors.affiliation: School of Natural Resources and Environment, University of Michigan, Ann Arbor, MI 48109 (perfecto@umich.edu).
authors.forename: Ivette
authors.initials: I
authors.lastname: Perfecto
authors.affiliation: Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109 (zhajianf@umich.edu; jvander@umich.edu).
authors.forename: John
authors.initials: J
authors.lastname: Vandermeer
mesh_terms: D000818:Animals; D001000:Ants / Q000502:physiology; D001487:Basidiomycota / Q000502:physiology*; D040503:Coffea / Q000382:microbiology*; D032661:Cordyceps / Q000502:physiology*; D004175:Diptera / Q000502:physiology*; D008800:Mexico; D010572:Pest Control, Biological; D010935:Plant Diseases / Q000517:prevention & control*; D018515:Plant Leaves / Q000382:microbiology; D011647:Puerto Rico
keywords: agroecology; autonomous biological control; coffee; coffee leaf rust; community assembly