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ARS Home » Pacific West Area » Maricopa, Arizona » U.S. Arid Land Agricultural Research Center » Pest Management and Biocontrol Research » Research » Publications at this Location » Publication #369698

Research Project: Ecologically Based Pest Management in Western Crops Such as Cotton

Location: Pest Management and Biocontrol Research

Title: Insecticidal activity of marigold Tagetes patula plants and foliar extracts against the hemipteran pests, Lygus hesperus and Bemisia tabaci

Author
item Fabrick, Jeffrey
item YOOL, ANDREA - University Of Adelaide
item Spurgeon, Dale

Submitted to: PLoS One
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/8/2020
Publication Date: 5/19/2020
Citation: Fabrick, J.A., Yool, A.J., Spurgeon, D.W. 2020. Insecticidal activity of marigold Tagetes patula plants and foliar extracts against the hemipteran pests, Lygus hesperus and Bemisia tabaci. PLoS One. 15(5). https://doi.org/10.1371/journal.pone.0233511.
DOI: https://doi.org/10.1371/journal.pone.0233511

Interpretive Summary: The western tarnished plant bug (Lygus hesperus) and the whitefly (Bemisia tabaci) are important pests of many crops throughout western North America. Current management of these insect pests is reliant on only a few insecticides and is threatened by the development of resistance. Hence, new chemistries or alternative management strategies are needed to reduce resistance selection pressure and to enhance control of these pests. Here, we investigated the bioinsecticidal toxicity of the French marigold, Tagetes patula, against both L. hesperus and B. tabaci. Assays indicated significantly reduced survival of both pest species on T. patula plants, and in diet incorporation assays containing aqueous and methanolic marigold foliar extracts. Mortality was dose-dependent, indicating the presence of one or more extractable toxicants. These data suggest that T. patula plants have insecticidal constituents that might be identified and developed as novel alternatives to conventional chemical treatments.

Technical Abstract: The western tarnished plant bug, Lygus hesperus Knight (Hemiptera: Miridae) and the whitefly, Bemisia tabaci Gennadius (Hemiptera: Aleyrodidae) are key hemipteran pests of numerous crop plants throughout the western United States and Mexico. Management in the U.S. currently relies on only a few insecticides and is threatened by the evolution of resistance. New chemistries or alternative management strategies are needed to reduce selection pressure on current insecticides and enhance control. Here, we investigated the bio-insecticidal toxicity of the French marigold, Tagetes patula Linnaeus (Asterales: Asteraceae), against both L. hesperus and B. tabaci. Assays indicated significantly reduced survival of both pest species on T. patula plants, and in diet incorporation assays containing aqueous and methanolic marigold foliar extracts. Mortality was concentration-dependent, indicating the presence of one or more extractable toxicants. These data suggest that T. patula plants have insecticidal constituents that might be identified and developed as novel alternatives to conventional chemical treatments.