You may have to blink three times, but it really happens: in Emmen and Coevorden, a paintball gun is shot at trees. Oak to be exact. And not as a game, but to fight the oak processionary caterpillar.
“We call this mating disturbance,” says Silvia Hellingman. She has been researching the control of oak processionary caterpillars for years. Researchers shoot a lure into the trees with a paintball gun. It contains pheromones that upset the males. As a result, as butterflies, they no longer mate with the females and there are no eggs and therefore no new caterpillars.
This method was used for the first time last year. “It worked, but it took too much time,” Hellingman says. “We had to go through all those trees with a cherry picker.” Shooting from the ground with a rifle is much faster. “You can do a hundred trees per hour. And everyone can do this themselves in their own garden.”
Hellingman has discovered another benefit to the pheromones. “Only the male caterpillars are upset by it, it leaves the other insects alone.” This method has been used in southern Europe for years in parks, forests and public green spaces.
In the research, Hellingman is collaborating with a Swedish university, among others. One of their students is graduating on this subject. Fighting the oak processionary caterpillar with pheromones is supported by the province of Drenthe and the municipalities of Coevorden and Emmen. The study is expected to be completed in November next year.
Watch how a paintball gun shoots the pheromones into the trees: