Spatio-temporal dynamics of the invasive fly Drosophila suzukii (Diptera: Drosophilidae) in the irrigated valleys of Northern Patagonia, Argentina

. Drosophila suzukii (Matsumura) (Diptera: Drosophilidae) also known as “spotted wing Drosophila” is a po-lyphagous herbivore of Asian origin with a short life cycle, and high dispersal and reproduction rates. The ar-rival of this invasive pest forced a reevaluation of management strategies in Northern Patagonia. The aims of this work were to quantify the inter-annual variation of population levels, explore the influence of cultivat-ed and wild hosts, assess the dispersal of the pest, and adjust a statistical model to describing population patterns as a function of degree days and relative humidity. We selected a cherry and raspberry orchard lo-cated in Plottier, Neuquén. Transect sampling was carried out and 33 traps were placed across an área of 12.5 km2 between 2018 and 2023. D. suzukii used fruit crops such as peach, vineyard, and plum trees as alternate hosts. D. suzukii exhibited seasonal behavior, with higher captures observed during summer and autumn. The adjusted GAMM model showed an increase in captures at 1,500 degree days (DD) and popula-tion peaks between 3,000 and 3,200 DD. This model is the first to be used in Argentina with trap capture count. Unlike conventional models, it allows for the integration of nonlinear variables.