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Agricultural practices and the cascading effects of apparent competition: A case study of trophic interactions on cultivated maize and wild lima bean plants.

English title Agricultural practices and the cascading effects of apparent competition: A case study of trophic interactions on cultivated maize and wild lima bean plants.
Applicant Benrey Betty
Number 162860
Funding scheme Project funding (Div. I-III)
Research institution Institut de Zoologie Faculté des Sciences Université de Neuchâtel
Institution of higher education University of Neuchatel - NE
Main discipline Ecology
Start/End 01.10.2016 - 31.03.2020
Approved amount 372'000.00
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All Disciplines (2)

Discipline
Ecology
Agricultural and Forestry Sciences

Keywords (6)

multitrophic interactions; biological control; indirect plant-mediated effects; Apparent competition; Agricultural Ecosystems; parasitoids

Lay Summary (German)

Lead
Wir untersuchen die Bedeutung einer Wechselbeziehung, die sogenannte apparente Konkurrenz, bei der sich Organismen aufgrund der jeweils vorteilhaften Auswirkungen auf einen gemeinsamen natürlichen Feind gegenseitig negativ beeinflussen. Als biologisches System dient uns dabei der in Mexiko praktizierte kombinierte Anbau von Mais und Bohnen, mit den zugehörigen Schadinsekten sowie Schlupfwespen als deren Gegenspieler.
Lay summary

Apparente Konkurrenz (apparent competition) ist eine ökologische Wechselbeziehung, bei der sich Arten, ohne dass sie direkt etwas miteinander zu tun haben, gegenseitig negativ beeinflussen, weil sie gemeinsamen natürlichen Feinden ausgesetzt sind. Die Folgen der apparenten Konkurrenz erstrecken sich auf alle anderen Organismen, die mit diesen Arten interagieren, und sie wirkt sich somit auch auf die Diversität von Pflanzen- und Tiergemeinschaften aus. Wir werden dieses Phänomen an einem System erforschen, welches folgende Organismen umfasst: Mais als Kulturpflanze und wilde Limabohnen, Insekten, die sich von den Blättern und Samen dieser beiden Pflanzen ernähren sowie Schlupfwespen, welche die Larven dieser pflanzenfressenden Insekten parasitieren. Wir werden untersuchen, wie sich landwirtschaftlichen Praktiken, mit oder ohne Pestizideinsatz, in diesem komplexen System auf die apparente Konkurrenz zwischen den Pflanzenfressern auswirken. Traditionelle Praktiken, in denen Mais und Bohnen zusammen angebaut werden, kommen in Entwicklungsländern häufig vor, besonders in Mexiko. Die Insektenschädlinge können auf diesen Kulturpflanzen verheerende Schäden verursachen, nicht nur auf den Feldern, sondern auch in Nahrungsmittellagern. Kenntnisse darüber, wie sich diese Arten direkt oder indirekt über vermittelnde Drittorganismen gegenseitig beeinflussen, können hilfreich dabei sein, Strategien für den Schutz dieser und anderer Kulturpflanzen gegen Schädlinge zu entwickeln.

Direct link to Lay Summary Last update: 05.08.2016

Responsible applicant and co-applicants

Employees

Publications

Publication
Parasitoids of leaf herbivores enhance plant fitness and do not alter caterpillar‐induced resistance against seed beetles
Bustos‐Segura Carlos, Cuny Maximilien A. C., Benrey Betty (2020), Parasitoids of leaf herbivores enhance plant fitness and do not alter caterpillar‐induced resistance against seed beetles, in Functional Ecology, 34(3), 586-596.
Host density and parasitoid presence interact and shape the outcome of a tritrophic interaction on seeds of wild lima bean
Cuny Maximilien A. C., Traine Juan, Bustos-Segura Carlos, Benrey Betty (2019), Host density and parasitoid presence interact and shape the outcome of a tritrophic interaction on seeds of wild lima bean, in Scientific Reports, 9(1), 18591-18591.
Role of cyanogenic glycosides in the seeds of wild lima bean, Phaseolus lunatus: defense, plant nutrition or both?
Cuny Maximilien A. C., La Forgia Diana, Desurmont Gaylord A., Glauser Gaetan, Benrey Betty (2019), Role of cyanogenic glycosides in the seeds of wild lima bean, Phaseolus lunatus: defense, plant nutrition or both?, in Planta, 250(4), 1281-1292.
Changes in plant growth and seed production in wild lima bean in response to herbivory are attenuated by parasitoids
Cuny Maximilien A. C., Gendry Johanna, Hernández-Cumplido Johnattan, Benrey Betty (2018), Changes in plant growth and seed production in wild lima bean in response to herbivory are attenuated by parasitoids, in Oecologia, 187(2), 447-457.
Back to the Origin: In Situ Studies Are Needed to Understand Selection during Crop Diversification
Chen Yolanda H., Shapiro Lori R., Benrey Betty, Cibrián-Jaramillo Angélica (2017), Back to the Origin: In Situ Studies Are Needed to Understand Selection during Crop Diversification, in Frontiers in Ecology and Evolution, 5, 1-8.

Scientific events

Active participation

Title Type of contribution Title of article or contribution Date Place Persons involved
6th International Entomophagous Insects Conference Talk given at a conference Parasitoids of leaf herbivores and seed beetles can enhance the fitness of wild lima bean plants (talk Betty Benrey 09.09.2019 Perugia, Italy Benrey Betty;
19e Colloque de Biologie de l’Insecte Talk given at a conference Plant-mediated interactions with insects in wild and cultivated beans: cascading effects on different guild levels (invited plenary talk Betty Benrey 26.06.2019 Albi, France Benrey Betty;
Third Jack R. Harlan International Symposium Dedicated to the Origins of Agriculture and the Domestication, Evolution, and Utilization of Genetic Resources Talk given at a conference Consequences of plant domestication for resistance against insect herbivores: Case studies with Mesoamerican crops (talk Betty Benrey) 03.06.2019 Montpellier, France Benrey Betty;
Swedish Agricultural University Individual talk Cross-seasonal consequences of herbivory for tritrophic interactions on lima bean plants (invited talk Betty Benrey) 16.05.2019 Alnarp, Sweden Benrey Betty;
Gordon Research Conference on Plant-Herbivore Interaction Talk given at a conference Cross-Seasonal Consequences of Herbivory for Tritrophic Interactions (invited talk Betty Benrey) 24.02.2019 Ventura, California, United States of America Benrey Betty;
Annual Meeting Ecological Society of America Talk given at a conference The consequences of plant domestication for resistance against insects: testing the role of the plant-breeding target in Squash (invited talk Betty Benrey) 05.08.2018 New Orleans, Louisiana, United States of America Benrey Betty;
Annual Meeting Ecological Society of America Talk given at a conference Cascading effects of early-season herbivory on late-season herbivores and their parasitoids (invited talk Betty Benrey) 06.08.2017 Portland, Oregon, United States of America Benrey Betty;


Associated projects

Number Title Start Funding scheme
127364 Do plant-mediated indirect interactions among herbivores affect parasitoid performance and genetic population structure? 01.10.2009 Project funding (Div. I-III)
185319 Understanding and exploiting communication between cotton plants 01.10.2019 Project funding (Div. I-III)
197463 Unraveling the ecology behind the success of traditional Milpa intercropping in Mesoamerica 01.10.2020 Project funding (Div. I-III)
136184 Benzoxazinoid derivatives at the plant-insect interface: An integrated approach to understand a metabolic network 01.10.2011 Sinergia
134413 InvaVol: Consequences of insect invasions for plant-insect interactions mediated by volatile organic compounds 01.04.2011 Project funding (special)
183365 Ultra High Performance Liquid Chromatography-High Resolution Tandem Mass Spectrometry (UHPLC-HRMS/MS) for metabolomics and identification of bioactive molecules 01.10.2019 R'EQUIP

Abstract

Apparent competition is an ecological phenomenon whereby a species negatively affects another species at the same trophic level through the action of shared natural enemies. Importantly, the full consequence of apparent competition is not limited to one particular species, but extends to all other organisms that interact with this species. We postulate that agricultural practices, with and without the use of pesticides, will strongly affect apparent competition between insect herbivores in agricultural and neighbouring natural ecosystems. These indirect effects will have tremendously important consequences for the presence and performance of insects throughout the season in both systems. This idea is based on the notion that the natural enemies of insect herbivores are particularly sensitive to pesticides and that this important mortality factor will affect the flux of natural enemies of herbivores from a crop to neighbouring wild plant populations and vice versa. We propose to study these cascading effects in cultivated maize and wild lima bean, which grow side by side throughout Mexico. Spodoptera frugiperda, the most important foliar pest of maize, has developed resistance against pesticides. We found many S. frugiperda larvae surviving in treated fields, but none were parasitized. In contrast, larvae on nearby non-treated maize were frequently parasitized. Lima bean plants are attacked by another Spodoptera species, which shares the same parasitoids, leading to reciprocal apparent competition. Moreover, in lima bean early season herbivory can significantly reduce late season seed production and induces chemical changes that affect the performance of seed-feeding beetle larvae, as well as their parasitoids. Shortly after, different beetles attack maize cobs, and their larvae again share several parasitoids with the beetles on lima bean. This results in a new apparent competition event and brings the cascading effects to full circle. We aim to study these effects by addressing the following inter-connected questions:A.How readily do parasitoids switch their foraging efforts from one plant-host complex to another, and what is the role of associated learning in this expected behavioural plasticity?B.What are the consequences of early season apparent competition between herbivores on maize and lima bean for late season plant-herbivore interactions on the same plants?C.How do pesticide treatments affect apparent competition and its cascading effects on maize and lima bean?Combining laboratory, field cage and open field experiments, we will conduct behavioural, performance and metabolomics assays. The results will provide unique insight into how early season apparent competition may affect late season apparent competition in an important agro-ecosystem. Besides contributing to fundamental ecology theory, the work will generate knowledge that will be of use for the development of cropping strategies that optimize the presence and efficacy of native biological control agents.
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