Posted on | June 17, 2010 | 3 Comments
The USDA Animal and Plant Health Inspection Service this week ceased release and transport of the Chinese or salt cedar leaf beetle because of potential impact on habitat of the Southwestern Willow Flycatcher. Since 1999, the beetles have been introduced along riverbanks in more than a dozen western states to check the spread of tamarisk trees, also known as salt cedars, introduced plants that are thought to displace natives and take too much water. However, incursion by the beetles into Arizonan flycatcher territory last year prompted a lawsuit. At issue: the endangered bird nested in the acclimated tree, which in turn was increasingly being eaten by an introduced beetle.
The decision to halt release of the beetle (Diorhabda elongata) comes on the heels of a series of reports finding that the threats posed by tamarisk to the water supply have been overblown while the plant’s benefits were obscured by the politics of drought. Last year, “The Monstering of Tamarisk” by Arizona State University biologist Matthew Chew characterized the massive federal tamarisk eradication effort as having taken on a life of its own, while a team from the University of Arizona and US Geological Survey reported in Southwest Hydrology that tamarisk “water use is well within the range of native species” such as cottonwoods and willows. This was echoed in April by an USGS study.
This post has been updated.