Abstract
Strategies to control infectious incurable disease that require coordination of prevention or mitigation efforts face challenges when individual and societal preferences do not align or when confidence in scientific information is low. We explore these conditions using the case of Huanglongbing (HLB) that ravaged Florida’s citrus industry within twenty years of the first discovery of Asian citrus psyllid (ACP) in 1998. ACP vector Candidatus Liberibacter asiaticus (CLas), the presumptive causal agent for HLB. ACP were discovered in California in 2008 and are now established in southern and coastal California commercial citrus producing region. HLB, however, has been kept within California’s residential citrus trees until a Clas-infected ACP was found in a commercial grove in 2021. Our analysis explores a stylized example of the California situation. We adapt an agent-based model of HLB to representative California citrus growers and their trees incorporating estimated survival functions capturing other grower behavior and HLB spread, and an information updating rule dependent on grower’s information confidence. We find gains in spray efficacy significantly delay the spread of HLB. Coordinated spraying also slows the spread of HLB, but a grower’s participation in coordinated spraying has little influence on when the infection reaches them. A higher belief in neighbors’ cooperation corresponded with increased free-riding, faster HLB spread, and lower cumulative profits while increased confidence in scientific information lowered HLB spread and increased cumulative profits. These findings suggest that a successful strategy to combat an incurable infectious disease like HLB requires careful consideration of how individual risk perceptions and trust in scientific information affect participation in coordinated mitigation activities.