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ARS Home » Southeast Area » Gainesville, Florida » Center for Medical, Agricultural and Veterinary Entomology » Mosquito and Fly Research » Research » Publications at this Location » Publication #381656
Research Project: Integrated Pest Management of Mosquitoes and Biting Flies

Location: Mosquito and Fly Research

Title: Plant essential oils enhance the vapor toxicity and repellency of spatial repellent pyrethroids

Author
item Norris, Edmund
item BLOOMQUIST, JEFFREY - University Of Florida

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 2/12/2021
Publication Date: 2/25/2021
Citation: Norris, E.J., Bloomquist, J.R. 2021. Plant essential oils enhance the vapor toxicity and repellency of spatial repellent pyrethroids. Emerging Pathogens Institute Research Day. p.73.

Interpretive Summary:

Technical Abstract: Effective control of vector-borne disease requires new types of insecticides and repellents, especially in light of widespread resistance to existing products. Screening of new repellents and insecticidal compounds was conducted in a glass tube assay to assess vapor repellency effectiveness in 1-hr exposures to Aedes aegypti mosquitoes and mortality assessments after a 24-hr exposure. As synergism of toxicity of topically applied pyrethroids by plant essential oils has been observed previously in our and other laboratories, we evaluated the potential of plant essential oils to synergize vapor toxicity of vapor active pyrethroids. For these studies, we screened a number of plant essential oils in combination with 3 vapor-active pyrethroids, metofluthrin, transfluthrin, and empenthrin. Synergism ratios were the largest and ranged from 2- to 380-fold for combinations of metofluthrin and fir needle and cedarwood-Virginian type oil, respectively. Synergism by plant essential oils was also observed in combinations with transfluthrin and empentrhin, with synergism ratios greater than 30 for transfluthrin and as high as 79 for empenthrin. Select essential oils also synergized the repellency produced by transfluthrin, with Amyris and cedarwood-Virginia being among the most potent enhancers. Interestingly, synergism ratios for plant essential oil/vapor active pyrethroid combinations were highly dependent on the plant essential oil in question, implicating specific bioactive constituents or mixtures thereof within the most synergistic plant essential oils. Future work will be performed to identify the specific constituents involved in this synergism and the potential mechanism(s) of action of these molecules.