Trail pheromone disruption of red imported fire ant

Area of Science:

• Entomology
• Chemical Ecology
• Invasive Species Management

Background:

• The red imported fire ant (Solenopsis invicta) is a highly invasive species causing significant ecological and economic damage.
• Current control methods like toxic baits harm non-target species and are unsuitable for sensitive environments.
• Fire ants utilize recruitment pheromones, specifically Z,E-alpha-farnesene, for efficient foraging and colony resource retrieval.

Purpose of the Study:

• To investigate the potential of disrupting fire ant trail orientation using an oversupply of the recruitment pheromone Z,E-alpha-farnesene.
• To assess the efficacy of Z,E-alpha-farnesene in disorienting Solenopsis invicta workers and hindering their trail-following behavior.

Main Methods:

• Z,E-alpha-farnesene was synthesized and presented from point sources to fire ant trails connecting colonies and food sources.
• Trail-following behavior was monitored using overhead webcams and analyzed with digital ant tracking software.
• Linear regression analysis (r²) was employed to quantify trail integrity before and after pheromone presentation.

Main Results:

• Fire ant workers initially exhibited strong trail integrity (r² = 0.75).
• Presentation of Z,E-alpha-farnesene rapidly disrupted trail-following behavior within seconds.
• Ants showed significant disorientation and reduced trail adherence near the pheromone source.

Conclusions:

• An oversupply of Z,E-alpha-farnesene effectively disorients foraging fire ants, disrupting their recruitment trails.
• This pheromone-based disruption presents a promising, non-toxic alternative for managing invasive fire ant populations.
• Further research is warranted to explore the long-term efficacy and control potential of this method for Solenopsis invicta.