Nicotinamide Inhibits Aphid Fecundity and Impacts Survival

Area of Science:

• Entomology
• Plant-Insect Interactions
• Molecular Biology

Background:

• Nicotinamide (NAM) is known to affect behavior in model organisms by acting on TRPV channels.
• This action mimics insecticides targeting phloem-feeding insects, suggesting potential applications in pest control.

Purpose of the Study:

• To investigate the impact of Nicotinamide (NAM) on the behavior of the green peach aphid (Myzus persicae).
• To evaluate NAM's potential as a pest control agent against aphids.

Main Methods:

• Artificial diet assays and foliar application of NAM to Arabidopsis plants were used to assess aphid feeding and survival.
• LC-MS analysis was performed on nicotinamidase (nic) mutant Arabidopsis plants to quantify NAM accumulation.
• Choice assays were conducted to observe aphid preference between NAM-treated and untreated plants.

Main Results:

• Dietary NAM impaired aphid stylet movement, leading to feeding interruptions, starvation, and death.
• NAM application to plants at 2.5 mM significantly increased aphid mortality and reduced feeding.
• Aphids avoided NAM-treated leaves, and reproduction was significantly decreased on Arabidopsis nic-1-1 mutants with high NAM levels.

Conclusions:

• Dietary NAM induces behavioral changes in aphids, including altered feeding, reduced reproduction, and increased mortality.
• NAM's effects are likely mediated by binding to TRPV channels, overstimulating sensory neurons in the aphid feeding apparatus.
• These findings support NAM as a potential agent for managing aphid populations by disrupting their feeding and reproductive behaviors.