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ARS Home » Southeast Area » Fort Pierce, Florida » U.S. Horticultural Research Laboratory » Subtropical Plant Pathology Research » Research » Publications at this Location » Publication #335673


Location: Subtropical Plant Pathology Research

Title: Different scenario-based simulations of ACP & HLB dynamics in Central Valley, CA for consideration of disease management

item POSNY, DREW - North Carolina State University
item LUO, WEIQI - North Carolina State University
item MCROBERTS, NEIL - University Of California
item Gottwald, Timothy

Submitted to: Journal of Citrus Pathology
Publication Type: Abstract Only
Publication Acceptance Date: 12/20/2016
Publication Date: 5/18/2017
Citation: Posny, D., Luo, W., McRoberts, N., Gottwald, T.R. 2017. Different scenario-based simulations of ACP & HLB dynamics in Central Valley, CA for consideration of disease management. Journal of Citrus Pathology. 4(1):34-45.

Interpretive Summary: A spatially-explicit agent-based model set in a realistic mixed landscape of residential and commercial citrus is utilized to conduct scenario-based simulations to investigate and inform ACP/HLB management strategies. Control strategies that included surveying for ACP and HLB, biological control with Tamarixia wasp to mitigate ACP and chemical control based on growers’ changing awareness, attitude and cost viability were simulated. A user-friendly front-end interface has been implemented for simulating different scenarios.

Technical Abstract: A better understanding of the transmission of HLB between the psyllids and citrus hosts in natural landscape is crucial to formulating effective control strategies. A spatially-explicit agent-based model, which simulates the actions and interactions of autonomous agents within the epidemiological system, has been developed to investigate how ACP and HLB spread in the Central Valley of California, an intermixed landscape of residential and commercial citrus. This study is a practical extension of the mathematical model with purposes to quantify the influence of input epidemiologic parameters on disease progress under sensitivity analysis, and investigate the efficiency of ACP/HLB management strategies by running scenario-based simulations. Although there are numerous hypothetical management strategies for testing, we focus more on survey design (i.e. disease detection level), and biological and chemical control strategies (i.e. frequency, timing, efficacy and coordination). In addition, we incorporated these management strategies into disease modelling with consideration of the social-economic perspective of citrus growers. Growers’ awareness of ACP/HLB and their attitude toward control strategies will change along with disease development, and we evaluate the set-points that yield optimal operation cost and sustainable control using a cost-benefit analysis. Our results indicate that climate change can have a large effect on the performance and spatiotemporal distribution of ACP and biological control agent populations in central California. ACP spread occurs more frequently and faster within commercial citrus clusters, but comparatively slower for low density or well separated residential areas. For different spray strategy scenarios, a comparison between simulation outputs confirms that the synchronize rate for coordinated spray plays an important role in slowing ACP epidemic development.