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 tabaciAuthor
Fabrick, Jeffrey | |
YOOL, ANDREA - University Of Adelaide | |
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. |