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LOGAN, Utah (AP) -- In the fight against noxious, nonnative weeds, Cache County officials are ditching expensive and toxic chemicals in favor of a biological solution -- insects.
"We find that if you bring in the natural enemy in the long run it pays off," Joel Merritt, Cache County weed supervisor said.
More than 20 different species of nonnative weeds have been found growing in the county. They can spread quickly and choke off native plants, Merritt said. In the past, the county has used machinery or chemicals to clear the invasive species.
But spraying poisonous compounds or plowing steep hillside fields isn't always feasible, so about eight years ago, the county began looking for alternatives and settled on bugs, Merritt said.
"They work 365 days a year, 24 hours a day, and work in places where chemicals dont," Merritt said. "The insects populate year after year and they basically work for you for free."
Cache County first used insects on the deep-rooted perennial plant known as Leafy spurge, which had overtaken fields near Richfield.
The county bought 2,000 beetles -- at $1 each -- and let them loose. The beetles eat the plant's leaves and lay eggs inside the root system. The larvae also cut off the supply of water and nutrients to the weed, Merritt said.
It takes about three years for the insects to have an effect, but Merritt said that once the bugs take control, the weeds disappear.
"I could take you to areas where we've gotten 75 to 80 percent control within five years," Merritt said. "We are getting places where native grasses are re-establishing."
The county weed department has also established five beetle "nurseries," where they house and distribute the rapidly reproducing bugs.
The practice of using biological controls has been common for nearly 100 years, said Amber Richman, biological control of invasive weeds technician at the Animal and Plant Health Inspection Service.
Before an organism can be used as a bio-control agent APHIS conducts laboratory and research site tests over 10 years before releasing it for use by the public. The process ensures the insects will only feed on the intended weeds, Richman said.
"We can pretty well guarantee that the agents we release now are 99.9 percent safe," Richman said. "They are so host specific and their biology is so highly tested that they dont affect anything except our targets."
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Information from: The Herald Journal, http://www.hjnews.com
(Copyright 2006 by The Associated Press. All Rights Reserved.)
