Location: Pest Management and Biocontrol ResearchTitle: Quantifying conservation biological control for management of Bemisia tabaci (Hemiptera: Aleyrodidae) in cotton
|VANDERVOET, T.F. - University Of Arizona|
|ELLSWORTH, P.C. - University Of Arizona|
|CARRIERE, Y. - University Of Arizona|
Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/7/2018
Publication Date: 5/28/2018
Publication URL: https://handle.nal.usda.gov/10113/6472277
Citation: Vandervoet, T., Ellsworth, P., Carriere, Y., Naranjo, S.E. 2018. Quantifying conservation biological control for management of Bemisia tabaci (Hemiptera: Aleyrodidae) in cotton. Journal of Economic Entomology. 111:1056-1068.
Interpretive Summary: The sweetpotato whitefly is a key pest of cotton in the southwestern USA and can severely impact lint quality through honeydew deposition if populations are not properly managed. Past research shows that biological control by a community of generalist arthropod predators is important to pest suppression and that conservation of these predators through the use of selective insecticides applied according to action thresholds is key to the pest's management in cotton. An ARS scientist in Maricopa, Arizona collaborated with researchers at the University of Arizona to develop action thresholds that take into account the abundance and activity of generalist predators. Experiments were conducted in which predator and whitefly populations were subject to a range of broad-spectrum and selective insecticide exclusions to order to manipulate predator : prey interactions. From this work the critical abundances of six key generalist predators relative to pest densities (predator:prey ratios) were identified and used to estimate candidate biological control informed thresholds for pest control. These ratios clarify the role of key predators in whitefly suppression, yielding potential decision-making advantages that could contribute in further improving sustainability of pest control in the cotton IPM system. These new biological control informed thresholds will assist cotton growers in reducing the risk associated with pest control decisions and ultimately provide for more cost-effective and environmentally sound pest management.
Technical Abstract: Conservation biological control can be an effective tactic for minimizing insect-induced damage to agricultural production. The most effective manner of applying CBC is through an Integrated Pest Management (IPM) strategy, combining many tactics including cultural controls, pest sampling, the use of action thresholds, and selective insecticides. Within the Arizona cotton system a suite of generalist arthropod predators provide critical regulation of B. tabaci and other pests. To refine conservation biological control in this system, we sought to identify key predators’ impact on the sweetpotato whitefly, Bemisia tabaci MEAM1 (Hemiptera: Aleyrodidae) in a 2-year field study. Predator and B. tabaci field populations were subject to a range of broad-spectrum and selective insecticide exclusions to manipulate predator : prey interactions. The critical abundances of six key generalist predators were identified, when B. tabaci densities were near the existing action threshold: Misumenops celer (Hentz) (Araneae:Thomisidae), Drapetis nr divergens (Diptera:Empididae), Geocoris pallens (Hemiptera:Geocoridae), Orius tristicolor (White) (Hemiptera:Anthocoridae), Chrysoperla carnea s.l. (Neuroptera:Chrysopidae), Collops spp. (Coleoptera:Melyridae). The ratios of these predator : B. tabaci were further assessed as a simple-to-use decision tool (biological control informed thresholds) in the current B. tabaci IPM strategy. The identification of key predators within the large, flexible food web of the cotton agro-ecosystem and estimation of predator : B. tabaci ratios clarifies the role of key predators in B. tabaci suppression, yielding potential decision-making advantages that could contribute in further improving sustainability of pest control in the cotton IPM system.