ESM_0 Photo. Entrainment of semiochemicals with Porapak ® Q plug from cylinders used in stimuli delivery in dog training platform. (DOCX) ESM_1 Fig. Educational scent platform. (PDF) ESM_2 Fig. Training platform stimuli layout and decline in response to no target scent. (PDF) ESM_3 Table. Evaluation of the dog detection performance as number of indications with decreasing amounts of scent molecules over time. (PDF) ESM_4_V1 Video. Educational scent platform in operation. (AVI) ESM_4_V2 Video. Placement of cotton scent pad and the location of the scent by dog on a pine (a non-host tree of the beetle). (AVI) ESM_4_V3 Video. The search, GPS tracking, and location of natural attacks. (AVI) ESM_4_V4 Video. The search, location of two adjacent natural attacks, and rewarding. (AVI) The dog detection allows timely removal by sanitation logging of first beetle-attacked trees before offspring emergence, preventing local beetle increases. Detection dogs rapidly learned responding to synthetic bark beetle pheromone components, with known chemical titres, allowing search training during winter in laboratory and field. Dogs trained on synthetics detected naturally attacked trees in summer at a distance of >100 m.

This research was funded by two grants from "The Södra Foundation for Research, Development and Education", Växjö, Sweden to AJ. FS & GB was supported by the Linnaeus programme 'Insect Chemical Ecology, Ethology and Evolution' (IC-E3, #217-2006-1750) at SLU and later to FS ('Rapid olfactory detection of insect and fungal damage in forests', #2013-1583) both from "The Swedish Research Council Formas". FS was further supported by EXTEMIT-K project financed by OP RDE at Czech University of Life Sciences Prague (CZ.02.1.01/0.0/0.0/15-003/0000433).