Neotropical Entomology (2021) 50, 654-661

Patrícia Pereira, Amanda Maria Nascimento, Bruno Henrique Sardinha de Souza and Maria Fernanda Gomes Villalba Peñaflor (2021)
Silicon supplementation of maize impacts fall armyworm colonization and increases predator attraction
Neotropical Entomology 50 (4), 654-661
Abstract: Supplementation with Silicon (Si) is well-known for increasing resistance of grasses to insect herbivores. Although the exact underlying mechanism remains unknown, Si accumulation interacts with the jasmonic acid-signalling pathway, which modulates herbivore-induced plant defences. We examined whether Si supplementation alters direct and induced indirect defences in maize plants in ways that deter the initial infestation by the fall armyworm Spodoptera frugiperda (JE Smith). We assessed the herbivore's oviposition preference, neonate and third-instar larval performance as well as the recruitment of a predator of young larvae, the flower bug Orius insidiosus (Say), by herbivore-induced plant volatiles (HIPVs). In choice tests, S. frugiperda deposited about two times more eggs on -Si than on +Si maize. The mortality of neonate S. frugiperda larvae was about sixfold higher in +Si compared to -Si plants, even though they consumed similar leaf area on both treatments. Although there were no mortality differences, Si supplementation also impacted third-instar larvae that gained about twofold less weight than those fed on -Si maize. In olfactometer assays, O. insidiosus was not attracted to volatiles of uninfested maize plants with or without Si supplementation, but it was attracted to those emitted by fall armyworm-infested plants, irrespective of whether plants received Si supplementation. However, when the flower bug could choose between the volatiles released from -Si and +Si fall armyworm-infested plants, it preferentially oriented to +Si fall armyworm-infested plant. Our results show that Si supplementation in maize may deter fall armyworm colonization because of greater direct defences and attractiveness of HIPVs to the flower bug.
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Link to article at publishers website
Database assignments for author(s): Amanda Maria Nascimento, Maria Fernanda Gomes Villalba Penaflor

Research topic(s) for pests/diseases/weeds:
resistance/tolerance/defence of host
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
environment/habitat manipulation

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Spodoptera frugiperda	Maize/corn (Zea mays)	Brazil (south)
Orius insidiosus (predator)	Spodoptera frugiperda	Maize/corn (Zea mays)	Brazil (south)