Disentangling the spread dynamics of insect invasions using spatial networks

Introduction Describing and understanding spatiotemporal spread patterns in invasive species remains a long-standing interdisciplinary research goal. Here we show how network-based top-down approach allows the efficient description of ongoing invasion by Drosophila suzukii Chile. Methods To do so, apply theoretical graph methods to calculate minimum cost arborescence (MCA) reconstruct understand dynamics D. since first detection 2017. This method estimates directed rooted weighted minimizing total length resulting graph. describe temporal pattern spread, estimate three metrics spread: median dispersal rate, coefficient diffusion, acceleration. Results The estimated MCA shows that over four years, colonized ~1,000km long strip central valley Chile, with an initial phase paths connections no clear direction pattern, followed clearer north–east propagation pattern. rate for entire period was 8.8 (7.4–10.6, 95% CI), while diffusion 19.6 meters 2 /day (13.6–27.9, CI). observed log-normal distribution accelerations are consistent long-distance events. Discussion complexities real landscapes cannot be summarized any model, but this study alternative based on theory can facilitate ecological analysis new territory.