Radiotelemetry unravels movements of a walking insect species in heterogeneous environments

The study of movements of individual organisms in heterogeneous environments is of primary importance for understanding the effect of habitat composition on population patterns. We developed a new experimental methodology to measure individual movements of walking insects, based on radiotracking. Our aims were to understand the link between habitat heterogeneity and moving patterns, and to characterize the movements with dynamic models of diffusion. We tracked individual movements of adults of Cosmopolites sordidus (Coleoptera: Curculionidae) with passive radio frequency identification (RFID) tags under different field management practices. Diffusion models based on recapture data indicated a subdiffusive movement of this species. Substantial variation was found between individual paths, but this variation was not sex dependent. Movement of released C. sordidus was affected by banana planting pattern and the presence/absence of crop residues but not by the presence of a cover crop between rows of bananas or by banana variety. These results show that the RFID technology is useful for evaluating the dispersal parameters of cryptic insects in heterogeneous environments. (Résumé d'auteur