Detection dogs recognize pheromone from spruce bark beetle and follows it to source: A new tool from chemical ecology to forest protection

Chemical ecology has already provided tools for monitoring, mass-trapping, and relocation of forest insects, especially in conifer bark beetles.

Here we demonstrate the use of detector dog to be effective for finding and locating spruces that has been recently infested by the European spruce bark beetle (Ips typographus L.), one of the most aggressive forest pests.

For active beetle management, attacked trees must be promptly removed (weeks) but are difficult to spot. Humans, who rely on visual cues for target identification of recent tree kills (still green), need to approach within <1 m, dogs use primarily olfactory cues and can therefore locate remote targets that are not visually obvious. The ability to search for target odour and then go to its source makes dogs ideal for rapid target recognition in field settings.

Dogs are trained on synthetic pheromone components, from both early and late stage attacks, on an educational platform (video) and later on trees before beetle swarming. Dog movement and detection distance data were collected during experiments with GPS. After beetle flight started, the dogs showed rapid and accurate orientation to single or groups of trees attacked, often over >50 m distance (video).

We observed detection distances ranging from 0.5 m to 150 m. Attacks of different ages (day –weeks) and standing or wind-felled trees were all detected. Scents from synthetic pheromone blends or natural pheromone seemed equally detectable for the dog. Detection limits and training of groups of private non-search dogs with their owners will be discussed.

Further applications may include detection of low-level attacks of alien or recently introduced pest insects.