Noxious weeds in Idaho
IDAHO CONSERVATION DISTRICTS,COUNTIES, SOUTHERN IDAHO “BUG CREW,” DEPLOY BIOCONTROL AGENTS TO COMBAT NOXIOUS WEEDS
The Squaw Creek and Gem soil and water conservation districts near Emmett have been experimenting with biocontrol agents on rush skeletonweed, poison hemlock and purple loosestrife since 2022 to reduce the spread of noxious weeds on private lands.
Leanne Buck, administrator for both districts, showed some “galls” forming on rush skeletonweed plants behind the District shop. The galls contain thousands of tiny mites working to retard the growth of the noxious weeds.
Buck is trying to create an “insectary” behind the district shop, where they could collect more mites to be used on other Rush skeletonweed plants elsewhere in the future.
The Nez Perce Biocontrol Center, based in Lapwai, sent an expert to Gem County in 2022 to help Buck and the districts release biocontrol agents to combat the spread of poison hemlock and purple loosestrife as well. That is one of the services provided by the Nez Perce Biocontrol Center, plus they store a variety of biocontrol agents for specific noxious weeds on site. Upon request, the agents can be sent to other conservation districts or county weed control officials in Idaho. There is no cost in acquiring the biocontrol agents from the Nez Perce Biocontrol Center. But they may charge for shipping or request that shipping containers be returned to keep their costs down.
All of Idaho’s county weed control programs, some conservation districts, and federal land management agencies are using biocontrol agents as part of a multi-pronged strategy to combat noxious weeds in Idaho. Counties and landowners are required by state law to control and prevent the spread of noxious weeds, but some are more active than others.
It’s expensive and sometimes cost- prohibitive to spray herbicides on large acreages of private or public lands to combat noxious weeds. Biocontrols can help slow the spread of some noxious weeds, and some biocontrols have been quite effective in nearly killing off the target weeds.“It is a slow process, but biocontrols can be effective,” Buck said.
