When Dale Janzen retired and moved to the mountain community of Arnold, California, he expected to live among healthy pine trees on his property. This hope was threatened by bark beetles.
“The drought was enabling the bark beetles to breed in unprecedented numbers, taking a devastating, deadly toll on the pine trees,” Janzen said. “The mountains were changing from green to brown.”
Janzen, however, wasn’t going to let the small community in the Sierra Nevada mountain range east of Stockton go unprotected. Through a career in agriculture, he had seen how the use of naturally–occurring semiochemicals, such as pheromones, could successfully control insect pests by manipulating their behavior. Janzen had worked in the Fresno, California area as a government inspector of fruit, nuts, and vegetables and had been recruited by the California Tree Fruit Agreement to represent California’s growers of peaches, plums, and nectarines in a collective that worked with universities and government agencies.
Janzen had seen how pheromones had successfully controlled two pest species, the omnivorous leaf roller and the peach twig borer.
In a strategy called mating disruption, the application of sex pheromones in orchards prevented the male moths from finding females for mating, which caused the pest populations to collapse. Janzen reported that five years after the U.S. Department of Agriculture licensed pheromone controls for these two pests, about 85 percent of California’s peach, plum, and nectarine growers were using pheromones instead of traditional toxic pesticides.
Faced with dying pine trees around his new home in Arnold, Janzen was happy to learn that ISCA’s SPLAT Verb was available to protect the pines.
Once the SPLAT Verb paste formulation is applied with a caulking gun to a pine tree, the product slowly releases a synthetic version of an anti-aggregation pheromone produced in nature by the mountain pine beetle. Called verbenone, this pheromone tells approaching beetles that the tree already has beetles present and they should look for another tree to infest. SPLAT Verb is essentially a “no vacancy” sign that keeps the beetles away.
Knowing that area-wide protection works best with this strategy, Janzen set out to convince his neighbors to try the product which expanded the area of protected trees in the community. “I went door to door in my neighborhood sharing my life experiences dealing with pheromones and what I had researched about SPLAT Verb in an effort to convince people to invest in the product at cost,” he said.
Committed to this effort to protect the trees, Janzen offered to help with initial costs by making free applications for those neighbors for whom cost was a hardship. “I also shared my story and experiences with the owners of the local Ace Hardware since they carry SPLAT and sell a large quantity of the product. I concentrated on my own area since I knew the neighbors personally and knew that adjacent properties treated with pheromone give a more effective buffer zone effect,” he said.
Janzen’s first order was 20 tubes, and he made free applications with 10 of the tubes. SPLAT Verb was applied on trees along a half-mile stretch of houses. “I was not disappointed to see a 90% success rate the first year…the “10% situations” were completely surrounded by infested trees. Last year I ordered 22 tubes at a discount. This year 27 tubes. I estimate our treated area to be around 10 acres.”
Janzen described those protected 10 acres around his and neighbors’ homes an island of healthy green pines. Unfortunately, the nearby unprotected forests were “just devastated,” he said.