News Release

 

 

For Immediate Release:  Nov. 21, 2002

Contact:  Jeff Fontana (530) 252-5332

CA-N-03-16

 

 

BLM ENLISTS TINY WEEVIL  IN NOXIOUS WEED FIGHT

 

The newest warrior in northeast California's battle against invasive weeds is also the tiniest.  It's a weevil, no bigger than a ladybug, but it holds great promise to tackle hundreds of acres of weed pests.

 

The Bureau of Land Management's (BLM) Eagle Lake Field Office, working with the California Department of Food and Agriculture (CDFA), has placed about a hundred Mediterranean sage root weevils into a stand of Mediterranean sage, a bushy, three-foot-tall, non-native weed that threatens to overrun a plot of public land east of Susanville.

 

"The weevils will spend the winter in the foliage, feeding on the plants.  Then, they will lay eggs.  When the larvae hatch in the early spring, they will feed on the root crowns and buds, damaging the ability of the plants to grow, mature and spread seeds," said BLM Botanist Carolyn Gibbs.

 

Gibbs, BLM Range Management Specialist Jennifer Mata and CDFA Entomologist Baldo Villegas collected the tiny black weevils from a site north of Lakeview, Ore. and moved them onto the 10-acre test plot near the Belfast Tablelands.  Additional weevils will be transplanted over the next twoyears to establish a resident population of the weed-eating insects. Agency specialists will monitor the population growth and the effects on the Mediterranean sage, which has infested more than 400 acres in the Belfast Tablelands area.

 

"It's a slow process, but we think it holds promise at reducing spread of this weed," Gibbs said.

 

The plant, commonly recognized as a kind of tumbleweed, spreads rapidly into range areas where it crowds out native plants needed for wildlife habitat.  It also out competes plants valuable for livestock forage.

 

"Just one plant can produce thousands of seeds, and they are easily spread as the wind blows the mature tumbleweeds across the landscape," Gibbs explained.

 

The weevil transplant is the latest in several methods being used the battle the Mediterranean sage spread on the tablelands.

 

Chemical trials are underway on two acres to determine which herbicide will kill the invading plants without harming the native vegetation.  Crews have installed snow fencing to prevent the tumbleweeds from blowing off the site, and plants have been ripped up along roads.

 

Gibbs said the Mediterranean sage weevil has shown promise since its introduction into the United States in 1971.  The insect, native to southern Eurasia, feeds only on the Mediterranean sage plants, and does not attack other species.  It has been used successfully in Oregon.

 

The BLM is working with other agencies and private landowners across the west to battle noxious weeds, defined by law as plants that injure public health, wildlife, recreation or property.  Left untreated, noxious and invasive weeds can overrun recreation areas, croplands and grazing areas.  They can crowd out other streamside vegetation, critical to wildlife.  Treatment and loss of productivity can cost millions of dollars.  Millions of acres across the west are infested.

 

In northeast California, more than two-dozen local, state and federal agencies are working together as the Lassen County Special Weed Action (SWAT) team.  The agencies cooperate to provide public education, and weed inventory information, and to control or eradicate weed infestations.

 

Information, including weed identification guidebooks, is available from the BLM's Eagle Lake Field Office, 2950 Riverside Dr., Susanville, or on the Internet at www.ca.blm.gov/eaglelake/noxweeds.html.

 

-BLM-

Eagle Lake Field Office - 2950 Riverside Drive - Susanville, CA  96130