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ARS Home » Southeast Area » Oxford, Mississippi » Natural Products Utilization Research » Research » Publications at this Location » Publication #346717

Research Project: Green Biopesticides: Identification

Location: Natural Products Utilization Research

Title: Mosquitocidal activity of a naturally occurring isochroman and synthetic analogs from the plant pathogenic fungus, Diaporthe eres against Aedes aegypti (Diptera: Culicidae)

Author
item Meepagala, Kumudini
item Estep, Alden - Navy Entomology Center Of Excellence, Cmave Detachment
item Clausen, Brandon
item Becnel, James

Submitted to: Journal of Medical Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/19/2018
Publication Date: 2/22/2018
Citation: Meepagala, K.M., Estep, A.S., Clausen, B.M., Becnel, J.J. 2018. Mosquitocidal activity of a naturally occurring isochroman and synthetic analogs from the plant pathogenic fungus, Diaporthe eres against Aedes aegypti (Diptera: Culicidae). Journal of Medical Entomology. 55(4):969–974. doi:10.1093/jme/tjy016.
DOI: https://doi.org/10.1093/jme/tjy016

Interpretive Summary: The fungi that can cause damage to the plants can produce compounds that are not only toxic to the plants but are toxic to insects and other fungi. When the fungi is grown in liquid that contain nutrients the fungus releases these toxic compounds to the liquid. These toxic compounds can be isolated and tested against adult mosquitoes and larvae. We have isolated such compounds from the liquid broth of a fungus that was harmful to English Ivy plants.

Technical Abstract: The culture filtrate of a plant pathogenic fungus that infects English ivy (Hegera helix) was investigated for mosquitocidal constituents by bioassay guided isolation. The fungus responsible for pathogenic effects on the plant Hegera helix has been identified as Diaporthe eres by molecular techniques. The mosquito adulticidal constituent in the culture filtrate was identified as 3,4-dihydro-8-hydroxy-3,5-dimethylisocoumarin (1) by spectroscopic techniques. Laboratory bioassays showed that (1) had larvicidal activity against permethrin susceptible and resistant Aedes aegypti strains. This compound was not significantly active as an adulticide when tested by topical bioassay. Several analogs of (1) were synthesized and showed that the analogs had better mosquitocidal activities than the naturally occurring (1).