The birds and the bee(tle)s

The end of a controversial tamarisk biocontrol program may be good news for habitat

  • Tamarisk trees along the Colorado River downstream of Moab, Utah, turn brown as tamarisk beetles gain a foothold. The native willows, bright green in the distant background, have been increasing here as the tamarisk continues to decline.

    Tom Dudley UCSB
  • Tamarisk beetle

    USDA Agricultural Research Service
  • Introduced tamarisk leaf beetles are now well-established on the Colorado Plateau, and spreading on their own. In June, the feds put the kibosh on a region-wide effort to use the beetles to kill invasive tamarisk, because the insects have spread into the Virgin River watershed (in the vicinity of St. George) where they could threaten nesting endangered southwestern willow flycatchers.

    the Tamarisk Coalition
 

The beetles are dead and gone, shriveled in the heat or eaten by ants, but otherwise the Owens Valley, Calif., research site looks the same as the last time scientist Tom Dudley saw it. Tinemaha Reservoir glimmers beyond a wall of brush. The sharp peaks of the Sierra Nevada decorate the skyline. Invasive Eurasian tamarisk, or saltcedar, trees still freckle the valley floor, their feathery branches casting long shadows across the native sagebrush in the early morning light. And Dudley's beige beetle cage, the last of a set, still envelops a single tamarisk, as if the five-foot cube of fabric could contain the plant and everything it stands for. Unzipping the mesh, Dudley steps inside with his screwdriver.

It's time to let go.

Dudley, a wild-haired, gray-bearded riparian ecologist from the University of California at Santa Barbara, is dismantling part of a more-than-decade-long research project on whether an Asian leaf beetle, Diorhabda elongata, can help rid the West of tamarisk. In June, partly in response to a lawsuit by the Center for Biological Diversity and the Maricopa Audubon Society, the U.S. Department of Agriculture's Animal and Plant Health Inspection Service (APHIS) indefinitely suspended its Diorhabda biocontrol program, including Dudley's research permits. It turns out that the insects -- a group of related species each about the size of a grain of rice -- may be threatening the endangered southwestern willow flycatcher, which nests in tamarisk in areas where the plant has displaced its preferred willow habitat.

The stakes holding down the cage are stuck in the ground, so with a rip and a clang Dudley uses a metal pole to pry the mesh away. He is frustrated with what he sees as putting the good of individual birds over the health of an ecosystem. "I'd prefer a system that was dominated by native species," he says. Finally the cage comes off, and he sets the plant free. "OK, bush, grow grow grow!" he says wryly.

Most Westerners have heard that tamarisks guzzle water, mess with soil salinity, push out native species, and destroy habitat. Land managers often crusade for its eradication. In the Owens Valley, the Inyo County Water Department spends around $300,000 a year fighting tamarisk with chainsaws and herbicides. The beetle, on the other hand, costs little to release. Under the right conditions, a few hundred insects can multiply across tens of thousands of acres in just three or four years. The larvae and adults strip tamarisk leaves summer after summer, gradually wearing groves into submission. Eventually, many trees die; the rest grow more modestly, their vigor and dominance reduced by the beetle's constant attacks.

Over the past decade, APHIS has permitted beetle releases in 18 states across the West and Midwest, and worked to establish nurseries of the insects in 10 of those. At many sites, the beetles failed to thrive, but at some they spread faster and farther than scientists had anticipated. Today, the insects swarm across the upper Colorado Plateau, and though no one tracks exact numbers, adding up local reports suggests they've defoliated tamarisk on a total of at least 11 million acres. By that measure, certainly, the beetle program has been a success.

But APHIS' recent decision makes it illegal to transport beetles across state lines. That means no new releases in states where the beetles aren't already established, such as Idaho and Washington –– much to the dismay of biocontrol supporters like Dudley. APHIS intended its moratorium to "raise awareness" and "encourage thought about intrastate movement" of the insects, and it has; in Montana and in the Owens Valley, for example, land managers have abandoned plans to use the beetles. Meanwhile, the insects are spreading deeper into flycatcher territory, and frustrated endangered species activists worry that APHIS' caution may have come too late to help the birds.

Yet despite all the furor, the agency's decisions –– both to approve the program in the first place and to suspend it now –– could well prove to be a net positive. The suspension may not close off all possibility for future biocontrol. And the march of the beetles is inspiring a new emphasis on proactive habitat restoration in flycatcher territory.

The current heart of the beetle saga is the Virgin River, a tamarisk-tinged Colorado River tributary that flows through Utah and Arizona before emptying into Nevada's Lake Mead. The Virgin hosts about 50 of the 1,300 willow-flycatcher nesting sites remaining in the Southwest, and connects, via the Colorado, to hundreds more. When APHIS began actively distributing leaf beetles in 2005, it agreed not to release any insects within 200 miles of the bird's known critical habitat. But insects have a way of ignoring boundaries.

According to the Center for Biological Diversity, APHIS employees allowed local officials in southern Utah to help themselves to some beetles from an approved nursery farther north in 2006. The Utah officials released the insects in the Virgin River watershed. Originally, the beetles couldn't survive so far south -- the  short  summer  days cued them to hibernate too early -- but they quickly adapted and began to thrive. Though scientists knew that might happen, they'd predicted it would take at least a decade. Instead, in 2008, the beetles crossed the invisible line into active flycatcher nesting territory, just a couple miles from the release area, and an unplanned, high-stakes experiment began.

High Country News Classifieds
  • GRAND CANYON DIRECTOR
    The Grand Canyon director, with the Grand Canyon manager, conservation director, and other staff, envisions, prioritizes, and implements strategies for the Grand Canyon Trust's work...
  • ADMINISTRATIVE ASSISTANT
    Great Old Broads for Wilderness seeks a part-time Administrative Assistant to support the organization's general operations. This includes phone and email communications, office correspondence and...
  • HISTORIC LODGE AND RESTAURANT - FULLY EQUIPPED
    Built in 1901, The Crazy Mountain Inn has 11 guest rooms in a town-center building on 7 city lots (.58 acres). The inn and restaurant...
  • ONE WILL: THREE WIVES
    by Edith Tarbescu. "One Will: Three Wives" is packed with a large array of interesting suspects, all of whom could be a murderer ... a...
  • PROGRAM DIRECTOR, SALAZAR CENTER FOR NORTH AMERICAN CONSERVATION
    The Program Director will oversee the programmatic initiatives of The Salazar Center, working closely with the Center's Director and staff to engage the world's leading...
  • WILDEARTH GUARDIANS - WILD PLACES PROGRAM DIRECTOR
    Salary Range: $70,000-$80,000. Location: Denver, CO, Portland, OR, Seattle, WA, Missoula, MT or potentially elsewhere for the right person. Application Review: on a rolling basis....
  • RIVER EDUCATOR/GUIDE + TRIP LEADER
    Position Description: Full-time seasonal positions (mid-March through October) Organizational Background: Colorado Canyons Association (CCA) is a 10 year old nonprofit organization fostering community stewardship of...
  • BOOKKEEPER/ADMINISTRATIVE ASSISTANT
    Position Description: Part-time, year-round bookkeeping and administration position (12 - 16 hours/week) $16 - $18/hour DOE Organizational Background: Colorado Canyons Association (CCA) is a 10...
  • LAND STEWARD
    San Isabel Land Protection Trust seeks a full-time Land Steward to manage and oversee its conservation easement monitoring and stewardship program for 42,437 acres in...
  • EXECUTIVE DIRECTOR
    Ventana Wilderness Alliance is seeking an experienced forward-facing public land conservation leader to serve as its Executive Director. The mission of the Ventana Wilderness Alliance...
  • COMMUNICATIONS AND DEVELOPMENT DIRECTOR
    The Quivira Coalition (www.quiviracoaltion.org) is a Santa Fe-based nonprofit that builds resilience on arid working lands. We foster ecological, economic, and social health through education,...
  • GRANT WRITER
    "We all love this place we call Montana. We believe that land and water and air are not ours to despoil, but ours to steward...
  • DEVELOPMENT DIRECTOR
    The Development Director is responsible for organizing and launching a coherent set of development activities to build support for the Natural History Institute's programs and...
  • WILDLIFE PROJECT COORDINATOR
    Founded in 1936, the National Wildlife Federation (NWF or Federation) is America's largest and most trusted grassroots conservation organization with 53 state/territorial affiliates and more...
  • EXECUTIVE DIRECTOR
    The Cinnabar Foundation helps protect and conserve water, wildlife and wild lands in Montana and the Greater Yellowstone Ecosystem by supporting organizations and people who...
  • TRUSTEE AND PHILANTHROPY RELATIONS MANGER,
    Come experience Work You Can Believe In! The Nature Conservancy in Alaska is seeking a Trustee and Philanthropy Relations Manager. This position is critical to...
  • EXECUTIVE DIRECTOR AT FRIENDS OF CEDAR MESA
    -The Land, History, and People of the Bears Ears Region- The Bears Ears and Cedar Mesa region is one of the most beautiful, complex, diverse,...
  • CONSERVATION SPECIALIST
    Position will remain open until January 31, 2021 Join Our Team! The New Mexico Land Conservancy (NMLC) is a non-profit land trust organization dedicated to...
  • OLIVERBRANCH CONSULTING
    Non-Profit Management Professional specializing in Transitional Leadership, Strategic Collaborations, Communications and Grant Management/Writing.
  • GREAT VIEWS, SMALL FOOTPRINT
    Close to town but with a secluded feel, this eco-friendly home includes solar panels, a graywater reuse system, tankless hot water, solar tubes, and rainwater...