Résumé
Highlights: • Trioza erytreae threatens the citrus groves of Europe, as a vector of huanglongbing. • A susceptible-infested-susceptible model simulates the spread of Trioza erytreae. • Landscape features, environmental variables and management options were considered. • Isolated elements within the landscape had significant effects on the species spread. • Control measures reduced abundances but were unable to halt the spread.Abstract: CONTEXT: The African citrus psyllid, Trioza erytreae (Del Guercio) (Hemiptera, Triozidae), is an invasive pest recently introduced into Europe, showing a particular preference for lemon trees (Citrus × limon (L.) Osbeck). It is also a vector of huanglongbing, the most damaging citrus disease, caused by the bacteria Candidatus liberibacter. Understanding the psyllid's spread dynamics across the landscape is crucial for future management and control of this pest.OBJECTIVE: A novel spatio-temporal modelling approach was developed to understand the spread dynamics of T. erytreae, and assess the effectiveness of insecticide management strategies in controlling its dispersal.METHODS: The study divided the landscape into patches representing specific land use/cover types. The spread of T. erytreae was simulated using a susceptible-infested-susceptible model, an adaptation of epidemiological approaches for landscape/agronomic contexts. The model's performance was evaluated by comparing simulation results with field observations. Additionally, the effectiveness of management strategies was tested by simulating the spread of the species in the landscape, with and without insecticide spraying.RESULTS AND CONCLUSIONS: Scattered citrus trees in residential areas were found to play a significant role towards the dispersal of T. erytreae, counteracting the effects of lemon orchard fragmentation and management strategies. Insecticide applications reduced the overall abundance of the psyllid but had no significant impact on its dispersal. Even under an extreme and intensive chemical control scenario, the probability of eradication was low, with only 25 % of simulations achieving eradication. The results obtained highlight the influence of the interplay between the landscape structure and management practices in the dynamics of pest species dispersal.SIGNIFICANCE: This study presents a novel method for modelling the population dynamics of multivoltine species in the scope of understanding the factors influencing their spread in agricultural landscapes. The insights gained could improve management strategies and planning, particularly the effectiveness of management strategies, with potential applicability to other pests and contexts.