A species-centered structural equation model reveals predator subsets driving biological control of Chilo sacchariphagus
Guinjard N., Rusch A., Tran A., Jacquelin F., Paulin L., Payet R.M., Mézino M., Le Mézo L., Soti V.. 2026. In : Franck P. (ed.), Lavigne C. (ed.), Begg G. (ed.), Lupi D. (ed.), Bischoff A. (ed.), Blight O. (ed.), Kergunteuil A. (ed.), Gauffre B. (ed.), Moonen C. (ed.), Monzó Ferrer C. (ed.), Hatt S. (ed.), Petit-Michaut S. (ed.). Working Group Landscape Management for Functional Biodiversity. Proceedings of the 11th Meeting at Avignon (France). Zurich : IOBC-WPRS, p. 189-193. (IOBC-WPRS Bulletin, 182). Meeting of IOBC-WPRS Working Group Landscape Management for Functional Biodiversity. 11, 2026-03-11/2026-03-13, Avignon (France).
Pest species are embedded in complex multitrophic networks that shape their dynamics. Systemic approaches integrating environmental covariates with multitrophic interactions are therefore needed to link biodiversity to agroecosystem functioning and design agroecological cropping systems. However, these approaches face methodological challenges, particularly when the focal herbivore occupies a narrow trophic module and the ecological processes shaping interactions remain poorly understood. We applied a species-centered structural equation modeling approach to identify drivers of sugarcane borer Chilo sacchariphagus infestation in sugarcane agroecosystems on Reunion Island. An intensive two- year survey at 60 sampling points disentangled direct and indirect effects of environmental factors while highlighting the role of generalist predators within a broader multitrophic context. A filtering procedure identified key predator species before constructing a tailored structural equation model. Our results show that a refined predator aggregate comprising 11 morphospecies with diverse functional profiles exerted a strong negative effect on pest damage (ß = –0.7). Additionally, the two dominant invasive ant species (Pheidole megacephala and Solenopsis geminata) exhibited a nonlinear, dome-shaped relationship with herbivory (ß1 = 0.5, ß2 = –0.6), suggesting a strong regulatory role. This study highlights the value of systemic approaches for understanding natural pest control. It underscores the importance of focusing on key predator groups while considering broader trophic interactions. Future research should clarify how predator functional traits complement each other and interact with the wider community to enhance pest regulation within the environmental context.
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Agents Cirad, auteurs de cette publication :
- Guinjard Nathan — Es / UMR TETIS
- Le Mezo Lionel — Persyst / UPR AIDA
- Mézino Mickaël — Persyst / UPR AIDA
- Paulin Louis — Persyst / UPR AIDA
- Payet Rose My — Persyst / UPR AIDA
- Soti Valérie — Persyst / UPR AIDA
- Tran Annelise — Es / UMR TETIS
