Location: Agroecosystem Management Research
Project Number: 3042-10400-001-005-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Jun 29, 2026
End Date: Jun 28, 2027
Objective:
1. Develop botanical-based repellent blends using essential oils listed under the EPA 25(b) minimum risk exemption that achieve maximum repellent activity and long-lasting effectiveness to protect humans and livestock from biting flies; and
2. Deliver a repellent formulation with the properties above that is suitable for use in a physical delivery device (vs. direct application).
Approach:
Natural product repellents have been used for hundreds of years to protect humans and animals from arthropod attack. Numerous studies have reported the repellency of plant-based essential oils of catnip (Nepeta cataria), citronella (Citronella citratus), geranium (Geranium spp), peppermint (Zanthoxylum piperitum), eucalyptus (Eucalyptus globulus) and lemongrass (Cymbopogon citratus), as well as short-chain-length fatty acids discovered from coconut oil. Although all these identified repellent compounds are effective against blood-sucking insects, one of the significant shortcomings is their short longevity with the effectiveness commonly lasting less than 8 hours. In contrast, medium chain fatty acids mainly act as deterrents rather than as spatial repellents. To overcome these challenges, we propose to develop a repellent with both spatial repellency and long-lasting effectiveness as a blood-feeding deterrent by blending different EPA exempted C25 listed compounds that contain the selected active ingredients mentioned above. Specifically, our approach is:
1. To develop effective repellent blends by integrating traditional folk remedies with essential oils listed under the EPA 25(b) minimum risk exemption, with the goal of achieving maximum repellency and extended duration of effectiveness.
2. To evaluate the enhanced repellent activity of the developed combined repellent compounds and essential oils, with emphasis on improving spatial repellency to inform the future design and development of a spatial repellent–releasing device.