, Volume 57, Issue 2, pp 331–347 | Cite as

Tamarisk biocontrol, endangered species risk and resolution of conflict through riparian restoration

  • Tom L. DudleyEmail author
  • Daniel W. Bean


A long-standing debate between wildlife agencies and biological control researchers and practitioners concerns Diorhabda carinulata Desbrochers (Coleoptera: Chrysomelidae) introduced to suppress invasive Tamarix spp. (Tamaricaceae), and potential impacts of Tamarix defoliation on endangered southwestern willow flycatchers using this non-native plant as nesting habitat in some western riparian ecosystems. The conflict and ensuing legal actions are currently centered on the presence of D. carinulata within the breeding range of the flycatcher in the Virgin River watershed, which has led to APHIS termination of permits supporting the biocontrol development program and has also affected other programs to develop biocontrol agents against environmental weeds. Central to concerns over wildlife is the lack of rehabilitation of native vegetation where biocontrol is expected, so there are current and planned efforts to promote restoration of native cottonwood-willow habitat to mitigate the anticipation decline in Tamarix cover. A strategic approach to riparian restoration is outlined which could facilitate sustainable, and scientifically documented recovery of this iconic habitat type. While the results of these efforts will not be known immediately, the process which is leading to riparian restoration has brought specialists from both sides of the debate together in search of resolution via collaboration, and if successful, may allow re-initiation of the Tamarix biocontrol program attendant with habitat enhancement for wildlife species of conservation concern.


Tamarisk Biological control Southwestern willow flycatcher Ecological restoration Riparian ecosystem Tamarix Diorhabda Coleoptera Chrysomelidae 



We greatly appreciate the continuing assistance of a multi-disciplinary research team that is evaluating tamarisk control and riparian restoration in the Virgin River watershed and elsewhere, particularly Meghan Taylor, Matthew Brooks, Steve Ostoja, Curt Deuser, Bill Longland, Heather Bateman, Mike Kuehn, Pat Shafroth, Kevin Hultine, Matt Johnson, Ben Conrad, Kumud Acharya, Bruce Orr, Glen Leverich, Derek Hitchcock, Jack DeLoach, Ken Lair and many others, and the guidance of the Clark County Desert Conservation Program (DCP), including John Brekke, Elizabeth Bickmore and Sue Wainscot. The on-going biodiversity enhancement program is particularly indebted to the support and facilitation from the Tamarisk Coalition (Stacy Kolegas, Shannon Hatch) and the Walton Family Foundation (Tim Carlson, Margaret Bowman), and benefits from productive discussion with participating biologists and managers including Mary Anne McLoed, Nora Caplette, Mark Sogge, Eben Paxton, Greg Beatty, Jeri Krueger, Theresa Olson, John Willis, Steve Meismer and many more. Work has been supported, in part, by grants from Clark County DCP (2005-UCSB-552-P), Forest Service Forest Health Protection (STDP R4-2004-01) and USDA-NRI (2006-35302). We dedicate this report to Brian Cardall, a colleague and friend who believed that tamarisk control and protection of our natural biodiversity can go hand-in-hand, and by working together we could actually make the progress that everyone involved is seeking.


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Copyright information

© International Organization for Biological Control (IOBC) 2011

Authors and Affiliations

  1. 1.Marine Science InstituteUniversity of CaliforniaSanta BarbaraUSA
  2. 2.Colorado Department of AgriculturePalisade InsectaryPalisadeUSA

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