The United States Department of Agriculture is investigating natural pest control methods to combat the emerald ash borer.
Doug Grimm of Grimm’s Gardens gave the Nebraska City Rotary Club an update on current and future treatment methods to combat the destructive insect on Wednesday afternoon.
Grimm said USDA representatives traveled to Asia to investigate natural pest control methods available in the borer’s native habitat.
U.S. and Chinese scientists have been looking for natural pest control options since 2003, according to an April 2017 article in Nursery Management magazine, which Grimm handed out to the audience.
Three parasitic wasp species have been identified in northeast Asia, and they have been approved for release in the U.S., according to the article.
Two of the wasp species attack emerald ash borer larvae, while the third attacks the borer’s eggs.
Grimm said widespread use of this natural pest control method may still be years away, depending on how fast the borer spreads.
Presently, ash tree owners can treat their trees with one of two insecticides, said Grimm.
One method can be applied by tree owners each spring, while the other requires a certified professional to apply it every two years.
Grimm said one of the best ways to prevent emerald ash borer is to ensure that the trees remain healthy.
“Emerald ash borers are attracted to unhealthy trees,” he said.
“If the tree stays healthy, it shouldn’t get emerald ash borers.”
When asked by the audience to recommend replacement trees, Grimm offered two sets of suggestions: replacement trees in stand-alone situations and replacement trees for situations in which other trees are around.
Among his stand-alone recommendations were ginko, locust and bald cypress, while he suggested American elm, sugar or rugged ridge maple, and sawtooth oak for landscapes with other existing trees.
Tomorrow’s speaker at the Nebraska City Rotary Club will be physical therapist Greg Cromer, who will talk about the new Husker Rehabilitation and Wellness Center, located at 115 S. 8th St.
The meeting begins at noon Wednesday, July 19, at the Eagle’s Club, 600 1st Corso. Guests pay $9 for lunch.