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Abstract Many infectious pathogens spend a significant portion of their life cycles in the environment or in animal hosts, where ecological interactions with natural enemies may influence pathogen transmission to people. Yet, our understanding of natural enemy opportunities for human disease control is lacking, despite widespread uptake and success of natural enemy solutions for pest and parasite management in agriculture.Here we explore three reasons why conserving, restoring or augmenting specific natural enemies in the environment could offer a promising complement to conventional clinical strategies to fight environmentally mediated pathogens and parasites. (a) Natural enemies of human infections abound in nature, largely understudied and undiscovered; (b) natural enemy solutions could provide ecological options for infectious disease control where conventional interventions are lacking; and, (c) many natural enemy solutions could provide important co‐benefits for conservation and human well‐being.We illustrate these three arguments with a broad set of examples whereby natural enemies of human infections have been used or proposed to curb human disease burden, with some clear successes. However, the evidence base for most proposed solutions is sparse, and many opportunities likely remain undiscovered, highlighting opportunities for future research. A freePlain Language Summarycan be found within the Supporting Information of this article.
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An aggressive nonconsumptive effect mediates pest control and multipredator interactions in a coffee agroecosystem
Abstract Natural pest control is an alternative to pesticide use in agriculture, and may help to curb insect declines and promote crop production. Nonconsumptive interactions in natural pest control that historically have received far less attention than consumptive interactions, may have distinct impacts on pest damage suppression and may also mediate positive multipredator interactions. Additionally, when nonconsumptive effects are driven by natural enemy aggression, variation in alternative resources for enemies may impact the strength of pest control. Here we study control of the coffee berry borer (CBB),Hypothenemus hampei, by a keystone arboreal ant species,Azteca sericeasur, which exhibits a nonconsumptive effect on CBB by throwing them off coffee plants. We conducted two experiments to investigate: (1) if the strength of this behavior is driven by spatial or temporal variability in scale insect density (an alternative resource thatAztecatends for honeydew), (2) if this behavior mediates positive interactions betweenAztecaand other ground‐foraging ants, and (3) the effect this behavior has on the overall suppression of CBB damage in multipredator scenarios. Our behavioral experiment showed that nearly all interactions betweenAztecaand CBB are nonconsumptive and that this behavior occurs more frequently in the dry season and with higher densities of scale insects on coffee branches. Our multipredator experiment revealed that borers thrown off coffee plants byAztecacan survive and potentially damage other nearby plants but may be suppressed by ground‐foraging ants. Although we found no non‐additive effects betweenAztecaand ground‐foraging ants on overall CBB damage, together, both species resulted in the lowest level of plant damage with the subsequent reduction in “spillover” damage caused by thrown CBB, indicating spatial complementarity between predators. These results present a unique case of natural pest control, in which damage suppression is driven almost exclusively by nonconsumptive natural enemy aggression, as opposed to consumption or prey behavioral changes. Furthermore, our results demonstrate the variability that may occur in nonconsumptive pest control interactions when natural enemy aggressive behavior is impacted by alternative resources, and also show how these nonconsumptive effects can mediate positive interactions between natural enemies to enhance overall crop damage reduction.
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- Award ID(s):
- 1853261
- PAR ID:
- 10373101
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Ecological Applications
- Volume:
- 32
- Issue:
- 7
- ISSN:
- 1051-0761
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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