Modeling the D. citri-HLB Pathosystem

Vector-borne plant diseases represent a complex phytosanitary challenge. Mathematical models serve as a key tool for analyzing integrated management strategies, enabling more effective control of these pests. A dynamical system is presented to model the infection of Tahiti lime (Citrus x latifolia) with the bacterium Candidatus Liberibacter asiaticus (CLas), transmitted mainly by infected adults of the psyllid D. citri, which causes the citrus greening—Huanglongbing (HLB). The proposed model is based on the D. citri-HLB pathosystem, basic interactions between bacteria, vector psyllid hosts, trees and a vector parasitoid wasp. It consists of nine ordinary differential equations that model the rates of change of the numbers of infected and uninfected vector nymphs and adult females, of infected and uninfected trees of high and low productivity, and of the parasitoid Tamarixia radiata, recommended for the biological control of D. citri. The parameters of the model are identified from extant literature or otherwise estimated, in both cases being adjusted to Colombian conditions. A mathematical analysis of a simplified model is carried out, and simulations are conducted to demonstrate the effect of different types of control easures.