Facilities crews at the University of Colorado Boulder are fighting the emerald ash borer with tree trunk injections.

The emerald ash borer is a highly destructive, non-native insect from Asia. If an ash tree is infected, it will die unless chemically treated. Facilities crews at CU are injecting insecticides directly into the trunks of threatened or infested trees. The targeted treatments are meant to reduce the area treated by chemicals.

“The only thing that's likely to be affected is anything that's going to be piercing and sucking the tissues of that tree or eating the leaf tissues of that tree,” said Vince Aquino, facilities operations lead arborist at the University of Colorado Boulder. “In the case of (ash trees), that's the emerald ash borers and then other possible problem insects like ash lilac borer and other insects that may feed on the leaves.”

Other treatments can include soil drenching. Gardeners define that as the process of adding diluted chemicals to the base of the plants.

A trial happening on the CU Boulder campus includes 56 trees. Forty two will receive treatments and 14 will be in a control group that do not receive insecticide treatments. Only 28 of the trial trees are receiving treatments this year. The goal of the study is to figure out the best methods for fighting off ash borer infestations.

Emerald Ash Borer infestations were first discovered in Colorado in 2013 and at CU Boulder in 2014.