Lost in translation: Pheromone, flight en masse or swarming, and Dave Wood

More than a million cubic meters of spruce trees were blown down in 1964 in Slovakia. An epidemic of Ips typographus was a threat. I studied the efficacy of our very laborious trap tree strategy and organized the salvage of fallen trees. Professor Wood’s team pioneering work identifying the chemistry of pheromonal attraction in Western bark beetles opened a new horizon for me. I wrote him and he showered me with reprints and numerous letters that helped me develop tests to determine whether pheromone communication existed in I. typographus. After much trial and error, we were able to plug 40 beetles into spruce bolts and test attraction against different treated bolts. The sometimes statistically significant catches did not appear to have the volume described as “flight en masse” (in my native language translated as “swarms”). I was unsure if a pheromone was responsible for the pattern I saw. I wrote David again, asking why swarming of bark beetles did not occur in the U.S., and why the response to the bolts with plugged beetles appeared so irregular in my experiments. David responded at length explaining “swarming” and “flight en masse” and enclosed Ipsdienol and Ipsenol ampoules for further tests. I prepared the test and, when the weather was just right, I attempted to carry the precious ampoules by motorbike to the forest. Suddenly a driver hit me in an intersection and the pheromones were released, far from my destination; no swarming or flight en masse occurred.