Remote sensing and GIS studies on the spatial distribution and management of Japanese beetle adults and grubs

Remote sensing and geographic information systems (GIS) are rapidly developing technologies that offer new opportunities and potentially more effective methods for detecting and monitoring insect pests, as well as understanding their spatial dynamics. These technologies (coupled with traditional trapping) were investigated for their use in managing Japanese beetle (Popillia japonica Newman) adults and grubs and studying their spatial distribution and dynamics. Japanese beetle grubs are important root-feeding pests of turfgrass in the Midwest and eastern United States. No non-invasive methods exist to detect grub infestations before unsightly damage has occurred. Studies were conducted to determine whether remote sensing could be used to detect the pre-visible symptoms of simulated and natural grub damage in turfgrass. Simulated grub damage was detected with surface temperature measurements (but not with spectrometer data) before significant visual differences were found. Plots infested with grubs were distinguished from uninfested plots using spectrometer data 10–16 days before significant differences in visual ratings were found. Results using multispectral imagery were mixed. Currently, Japanese beetles are not established in the western United States. There is great concern over their inadvertent transportation into Pacific costal states via cargo transport planes. Beetles may fly onboard cargo planes while they are loaded or unloaded and be accidentally transported to the western states. A study was initiated to evaluate trapping as a method to reliably detect Japanese beetle hotspots near cargo terminals at the Indianapolis International Airport and to assess the spatial variability of the population around the airport. The potential influence of land use on beetle abundance was also assessed, using a GIS. Baited Japanese beetle traps were placed around the perimeter of the airport and emptied daily. Location-dependent variation in trap catch was found. Seasonal average trap catches were highly correlated from year to year, by location. A mark-release-recapture study showed that Japanese beetles frequently flew up to 500m during a day, but could travel up to 700m. Using a GIS, a spatially explicit map of land use and trap location was created. Agricultural land within 500m of the traps was generally positively correlated with trap catch