The push-pull intercrop Desmodium does not repel, but intercepts and kills pests

  1. Anna L Erdei
  2. Aneth B David
  3. Eleni C Savvidou
  4. Vaida Džemedžionaitė
  5. Advaith Chakravarthy
  6. Béla P Molnár
  7. Teun Dekker  Is a corresponding author
  1. Swedish University of Agricultural Sciences, Sweden
  2. University of Dar es Salaam, Sweden
  3. University of Thessaly, Greece
  4. Plant Protection Institute, Hungary

Abstract

Over two decades ago, an intercropping strategy was developed that received critical acclaim for synergizing food security with ecosystem resilience in smallholder farming. The push-pull strategy reportedly suppresses lepidopteran pests in maize through a combination of a repellent intercrop (push), commonly Desmodium spp., and an attractive, border crop (pull). Key in the system is the intercrop's constitutive release of volatile terpenoids that repel herbivores. However, the earlier described volatiles were not detectable in the headspace of Desmodium, and only minimally upon herbivory. This was independent of soil type, microbiome composition, and whether collections were made in the laboratory or in the field. Further, in oviposition choice tests in a wind tunnel, maize with or without an odor background of Desmodium was equally attractive for the invasive pest Spodoptera frugiperda. In search of an alternative mechanism, we found that neonate larvae strongly preferred Desmodium over maize. However, their development stagnated and no larva survived. In addition, older larvae were frequently seen impaled and immobilized by the dense network of silica-fortified, non-glandular trichomes. Thus, our data suggest that Desmodium may act through intercepting and decimating dispersing larval offspring rather than adult deterrence. As a hallmark of sustainable pest control, maize-Desmodium push-pull intercropping has inspired countless efforts to emulate stimulo-deterrent diversion in other cropping systems. However, detailed knowledge of the actual mechanisms is required to rationally improve the strategy, and translate the concept to other cropping systems.

Data availability

https://figshare.com/articles/dataset/The_push-pull_intercrop_Desmodium_does_not_repel_but_intercepts_and_kills_pest/19297730

The following data sets were generated

Article and author information

Author details

  1. Anna L Erdei

    Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp, Sweden
    Competing interests
    The authors declare that no competing interests exist.
  2. Aneth B David

    Department of Molecular Biology and Biotechnology, University of Dar es Salaam, Dar es Salaam, Sweden
    Competing interests
    The authors declare that no competing interests exist.
  3. Eleni C Savvidou

    Department of Agriculture Crop Production and Rural Environment, University of Thessaly, Volos, Greece
    Competing interests
    The authors declare that no competing interests exist.
  4. Vaida Džemedžionaitė

    Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp, Sweden
    Competing interests
    The authors declare that no competing interests exist.
  5. Advaith Chakravarthy

    Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp, Sweden
    Competing interests
    The authors declare that no competing interests exist.
  6. Béla P Molnár

    Department of Chemical Ecology, Plant Protection Institute, Budapest, Hungary
    Competing interests
    The authors declare that no competing interests exist.
  7. Teun Dekker

    Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp, Sweden
    For correspondence
    teun.dekker@slu.se
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0001-5395-6602

Funding

No external funding was received for this work.

Reviewing Editor

  1. Youngsung Joo, Seoul National University, Republic of Korea

Version history

  1. Received: April 17, 2023
  2. Accepted: March 7, 2024
  3. Accepted Manuscript published: March 13, 2024 (version 1)

Copyright

© 2024, Erdei et al.

This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.

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  1. Anna L Erdei
  2. Aneth B David
  3. Eleni C Savvidou
  4. Vaida Džemedžionaitė
  5. Advaith Chakravarthy
  6. Béla P Molnár
  7. Teun Dekker
(2024)
The push-pull intercrop Desmodium does not repel, but intercepts and kills pests
eLife 13:e88695.
https://doi.org/10.7554/eLife.88695

Share this article

https://doi.org/10.7554/eLife.88695

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