Dissipation and Efficacy of Afidopyropen for Controlling Asian Citrus Psyllids Under Field Conditions

Citrus greening disease ravages citrus production globally. Thus, investigating disease management strategies and newly developed insecticides' effectiveness in the field is needed. In this field study, citrus trees were sprayed with afidopyropen at a commercial grove in Florida. Insecticide spatial distribution and dissipation kinetics were investigated in leaves and sample disks attached to leaves. Reductions of the target pest, Asian citrus psyllids (ACP), were quantified over time. Our findings show variable distribution to opposite leaf sides and canopy areas within individual trees. Dissipation half-lives ranged from 2.3 to 3.4 h. Afidopyropen initially reduced ACP by 65-100%. When ACP remained after treatment, efficacy decreased over time and ACP increased by 6-172%. Inadequate spatial distribution and rapid dissipation allow the remaining ACP to spread citrus greening disease to unprotected trees. Since afidopyropen is a target-site-of-action and semisystemic insecticide, full coverage to both sides of the leaves and canopy is crucial to effectively manage ACP populations.