[By Chris Woodka: The Pueblo Chieftain Oct 26, 2009] The USA's Arkansas Valley has taken aim at the invasive trees and gotten rid of 9,000 acres of the pests in the last four years. It’s estimated that 67,000 acres along the Arkansas River and its tributaries are infested with tamarisk. “Since 2006, we’ve spent more than $1 million in controlling invasive species,” said Mary Miller, of the Natural Resources Conservation Service, the federal agency that has coordinated programs. “The majority of the money has been spent on the ground for the treatment of tamarisk.”
Last year, the NRCS, more than two dozen government agencies and 40 landowners spent a combined $248,000 to treat 2,400 acres in Fremont, Pueblo, El Paso, Huerfano, Las Animas, Otero, Bent and Prowers counties.
The programs mostly involved destroying tamarisk, with some areas being restored as well. Mechanical, chemical and biological methods were used, Miller said.
The largest areas were controlled with aerial spraying. Mechanical means, either by hand or with machines, are more time-consuming and costly, but more effective in some areas. Biological control usually means releasing beetles that eat tamarisk, and only tamarisk.
Board member Leroy Mauch asked how effective beetles have been in controlling tamarisk, saying insects that control some noxious weeds have shown good results.
“It takes them two to three years to become established,” said Patty Knupp, wildlife biologist.
Beetles introduced in Fremont County have begun to defoliate tamarisk some distance away from where they were released. The beetles are species-specific and do not totally destroy plants, Knapp said.
“We’ll never totally eradicate tamarisk, but we’re doing the initial assault,” Knupp said. “The beetles control it.”