Detection of bark beetle infestations by drone and image analysis in spruce forests

Bark beetles, such as the eight-toothed spruce bark beetle (Ips typographus L.) and the six-toothed spruce bark beetle (Pityogenes chalcographus L.), cause extreme economic and environmental damage in forests, especially in areas dominated by Norway spruce (Picea abies L. Karst.). Fast detection and containment of bark beetle outbreaks are crucial in the battle against bark beetles, but unfortunately, the infestation detection system in Slovenia is somewhat outdated. As part of a research project, an experiment was conducted using a drone and a multispectral camera to search for bark beetle infestations. The experiment covered a forested area of 21.02 hectares, which was surveyed by the drone to capture images with the multispectral camera. By processing the collected data, an orthomosaic and NDVI index were created. Based on the analysis of the NDVI index, potential locations of bark beetle infestations were identified. The actual conditions in nature were verified through physical inspection of the area. The results of the experiment revealed that in all three areas where bark beetle infestations were predicted, Norway spruce trees showed signs of attack by the eight-toothed spruce bark beetle were present.