Salinity Influences Plant-Pest-Predator Tritrophic Interactions.

Area of Science:

• Agricultural Science
• Ecology
• Environmental Science

Background:

• Climate change drives soil salinity, threatening crop production and food security.
• The impact of salinity on plant-herbivore-natural enemy interactions and pest suppression is poorly understood.

Purpose of the Study:

• To investigate the effects of increased salinity on rice (Oryza sativa), brown planthopper (BPH), and green mirid bug (GMB) populations.
• To understand how salinity influences tritrophic interactions and pest suppression services in rice ecosystems.

Main Methods:

• Greenhouse experiment evaluating salinity effects on rice cultivars, BPH, and GMB.
• Measurements included plant growth, BPH and GMB population densities, and plant quality indicators.

Main Results:

• Elevated salinity suppressed rice growth and reduced host plant quality for BPH.
• BPH and GMB population densities decreased with increasing salinity, with peak BPH at 2.0 dS/m.
• Salinity induced asynchrony between BPH and GMB, potentially disrupting predator-prey dynamics.

Conclusions:

• Increased salinity negatively impacts rice plants, herbivores, and natural enemies.
• Salinity weakens bottom-up effects of natural enemies on rice pests, reducing pest suppression.
• Findings highlight the need for resilient pest management strategies in saline-affected rice production landscapes.