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