Occupancy and detection of agricultural threats: the case of Philaenus spumarius, European vector of Xylella fastidiosa

Occupancy models estimate presence and detection probability of species of interest of which they provide useful information and also contribute to decision making. In this proof-of-concept, we propose an approach to demonstrate the applicability of occupancy models in insect monitoring having as targets the spittlebug Philaenus spumarius, the main European vector of Xylella fastidiosa, and other spittlebugs. Surveys were performed in two different agricultural settings (olive orchards and vineyards) in Trentino (northern Italy). Philaenus spumarius was present in all surveyed sites and its detectability was significantly influenced by site covariates (i.e., forest and vineyard coverage, hours of sunlight) and plot covariates (i.e., weed height). Site covariates influenced the detection probability of other spittlebugs as well, while the co-occurrence of different species did not affect the P. spumarius occupancy. Our outcomes suggest that occupancy models are valuable tools that should support future studies aimed at estimating the presence and abundance of pest insects, especially when site covariates and/or sampling methods affect the detectability of a species