Intercrop movement of heteropteran predators between alfalfa and maize examined by stable isotope analysis
Alfalfa is a reservoir providing natural enemies to adjacent crops. However, whether these crops act only as receptors or also as donors is unknown. The pattern of movement between alfalfa and maize of Orius majusculus, Orius niger and Nabis provencalis and the role of both crops as “donor” or “receptor” were inferred through carbon and nitrogen stable isotope analysis. Results show that all heteropteran species are able to move between crops, but the predators’ movement is species specific and the role of alfalfa and maize as “donor” or “receptor” varies. The movement is also affected by crop management practices such as alfalfa cutting. All heteropterans that colonized maize at its early stage came from alfalfa, but N. provencalis also moved back to alfalfa from maize. Alfalfa cutting triggers movement of heteropterans to maize, but the time when this practice is performed also affects the movement. Alfalfa cutting did not have consequences on the recolonization of alfalfa, and some of the heteropterans found during the alfalfa regrowth period seem to have remained within alfalfa (mainly N. provencalis) while others came from maize (mainly O. majusculus and O. niger). When maize was harvested or dry, O. majusculus moved to alfalfa later than the other two predators. Due to the movement capacity of heteropterans between alfalfa and maize and the variable role of both crops as “donor” or “receptor”, conservation biological control could be enhanced by including adjacent fields of alfalfa and maize or a mosaic of both crops at farm and landscape levels.
KeywordsOrius majusculus Orius niger Nabis provencalis Anthocoridae Nabidae Dispersal Carbon and nitrogen stable isotopes
We thank the Cooperativa Pirenaica de La Seu d’Urgell and Josep Piqué for allowing us to use their fields for the experiments. We also thank Alejandro Juárez and Urs Kormann for statistics support and the three anonymous reviewers for their valuable comments.
This research was funded by the Spanish Ministry of Science and Technology, projects AGL2008-02355 and AGL2011-23996, and the Italian Ministry of Education, Universities and Research PRIN 2008WAFMX5. F. Madeira was also funded by a grant (BES-2009-020361) from the Spanish Ministry of Science and Technology.
Compliance with ethical standards
Conflict of interest
The authors have no conflict of interest to declare.
This article does not contain any studies with human participants or animals performed by any of the authors.
Informed consent was obtained from all authors included in the study.
- Inger R, Jackson A, Parnell A, Bearhop S (2010) SIAR V4 (stable isotope analysis in R): an ecologist’ s guide. https://www.tcd.ie/Zoology/research/research/theoretical/siar/SIAR_For_Ecologists.pdf. Accessed 25 Nov 2014
- Núñez E (2002) La alfalfa como reservorio de enemigos naturales. PhD thesis. Universitat de Lleida, Lleida, EspañaGoogle Scholar
- Núñez E, Rodriguez E, Perdiguer A (2007) Una alternativa para el control de plagas en la alfalfa: franjas sin cortar como refugio para la fauna auxiliar. Surcos de Aragón 101:26–30Google Scholar
- Parnell A, Jackson A (2014) SIAR: stable isotope analysis in R. http://cran.r-project.org/web/packages/siar/siar.pdf. Accessed 5 Sept 2014
- Pinheiro J, Bates D, DebRoy S, Sarkar D and R Core Team (2017) nlme: Linear and nonlinear mixed effects models. R package version 3.1–131. https://CRAN.R-project.org/package=nlme. Accessed 3 Feb 2018
- Pons X, Eizaguirre M (2009) Cultivos extensivos en regadìo: cereales, maìz y alfalfa. In: Jacas JA, Urbaneja A (eds) Control Biológico de Plagas Agrícolas. Phytoma, Valencia, pp 384–398Google Scholar
- Ponsard S, Arditi R (2000) What can stable isotopes (δ15N and δ13C) tell about the food web of soil macro-invertebrates? Ecology 81:852–864Google Scholar
- R Development Core Team (2012) R: a language and environment for statistical computing. R Foundation for Statistical Computing, Version 2.15.0, ViennaGoogle Scholar
- Ritchie SW, Hanway JJ, Benson GO (2005) How a corn plants develops. Special Report No. 48. Iowa State University of Science and Technology, Cooperative Extension Service, AmesGoogle Scholar
- Rossi P (2017) Bayesian inference for marketing/micro-econometrics. https://cran.r-project.org/web/packages/bayesm/bayesm.pdf. Accessed 2 Nov 2017