Flatten the huanglongbing (HLB) curve! The importance of IPM to limit its vector, the Asian citrus psyllid

Huanglongbing (HLB) is a disease of citrus trees that devastates production areas. Current strategies focus on control of the psyllid Diaphorina citri, the insect vector that transmits the disease. Insecticides have been used frequently, but their continuous use threatens the environment and human health, and does not eliminate inoculum sources outside the commercial areas. Therefore, complementary strategies have been proposed, such as external management, which comprises biological control together with eradication of inoculum sources from non-commercial groves. Here, we developed a computational model to simulate a landscape composed of a commercial farm and non-commercial groves. Inside the farm, we simulated the effect of chemical control on insect populations; outside, we simulated the effect of external management comprised of biological control with T. radiata and elimination of infected trees. Our model indicated that strategies applied externally are essential to flatten the HLB curve, since we demonstrated that the total number of infected trees is more sensitive to these strategies. We verified that chemical control was not able to protect farm borders, but an approach that combined chemical control + external management was able to protect most trees within the farm, including the border. Our model opens broad prospects for future studies and alerts growers to the need to consider external management for controlling HLB.