Large-scale acoustic detection of beetles in grain storage using the “Beetle Sound Tube”-System

Abstract: The “Beetle Sound Tube”-system has been developed for early detection of insect
infestation in grain storage. Large perforated metal tubes were inserted in the grain mass that
were supposed to bundle insect signals from the surrounding grain and lead it to a microphone inside the tube. The tube was also used as a trap to sample the insect population surrounding the tube. While the acoustic detection worked with granary weevils Sitophilus granarius the sounds of much smaller beetles that were predominantly present in the storage facilities in our project were not audible inside the tube. Therefore, the focus of the project was changed from sounds originating in the grain to sounds produced by trapped beetles inside the collection containers. While we started with an acoustic tube with trap function by now, the system changed to a beetle trap with built-in acoustic detection and evaluation unit which makes it more sensitive and less susceptible to acoustic disturbances and more suitable for practical use in storage facilities.