Aqueous 2% geraniol as a mosquito repellent failed against Aedes aegypti on ponies.

This research study investigated the effectiveness of a plant-derived alcohol, Geraniol, as a mosquito repellent for horses. The study found that a 2% aqueous solution of Geraniol applied on ponies did not demonstrate significant effectiveness in repelling Aedes aegypti mosquitoes.

Background

• Organic insect repellents can be of interest to animal owners and farmers due to their environmental sustainability.
• Geraniol is a plant-derived alcohol that is naturally produced by a variety of plants and is considered a minimum risk pesticide by the U.S. Environmental Protection Agency.
• Despite previous studies demonstrating the insect repelling and killing properties of various concentrations of geraniol, it’s also known to potentially cause allergic contact dermatitis in both humans and animals.

Methodology

• In this study, the researchers examined the effectiveness of a 2% aqueous solution of Geraniol, commercially available, sprayed on ponies to repel mosquitoes.
• Five trials were conducted where ponies were treated with a 60-ml aerosol mist (30 ml per side) of the 2% Geraniol solution or left untreated as a control group. The animals were observed three hours post-application to check for skin irritation.
• To assess the effectiveness of the geraniol treatment, Aedes aegypti mosquitoes in feeding tubes were then held on the ponies for seven minutes.

Results and Conclusion

• The average bite rate on control animals was 56%, with a range of 16-90%. However, the average bites for treated ponies was 13%, ranging from 0-86%.
• Statistical models showed no significant difference (P = 0.081) in the percent bites between treated and untreated animals three hours post application.
• Therefore, the study concluded that a 2% geraniol solution is not an effective mosquito repellent for horses.
• Importantly, no skin irritation was observed on the horses treated with the 2% geraniol solution, confirming that while it may not be an effective repellent, it does not cause harm to the animals’ skin.