Niche construction and niche choice by aphids infesting wheat ears

Area of Science:

• Ecology
• Plant-Insect Interactions
• Chemical Ecology

Background:

• Aphid feeding on plant phloem sap defines their ecological niche.
• Organisms can modify their environment through niche construction, impacting their fitness and offspring.
• Understanding plant-aphid interactions requires investigating aphid-induced changes in phloem sap and their effects on other aphids.

Purpose of the Study:

• To determine if aphids (Sitobion avenae) alter the chemical composition of wheat (Triticum aestivum) phloem sap.
• To assess if prior aphid infestation affects the fitness of subsequent aphid colonizers.
• To investigate aphid preference for previously infested versus uninfested host plants.

Main Methods:

• Wheat ears were either infested with Sitobion avenae or left uninfested.
• Phloem sap exudates were analyzed for metabolic composition using amino acid profiling and metabolic fingerprinting.
• Aphid colony growth and aphid choice behavior were assessed on previously infested and uninfested wheat ears.

Main Results:

• Sitobion avenae infestation altered the relative concentrations of metabolites in wheat phloem sap, notably increasing asparagine.
• Aphid colonies grew significantly larger on previously aphid-infested wheat ears compared to uninfested ears.
• Aphids demonstrated a clear preference for previously infested wheat ears in choice experiments.

Conclusions:

• Sitobion avenae actively engage in niche construction by modifying wheat phloem sap.
• Aphids exhibit niche choice by selecting previously infested plants, indicating a preference for their constructed environment.
• The study highlights the complex interplay between niche construction and niche choice in aphid-host plant interactions.