TUCSON (CN) - Environmentalists say the federal government illegally introduced one nonnative species to kill another one. The Center for Biological Diversity claims the U.S. Department of Agriculture's Animal and Plant Health Inspection Service's endorsement of a beetle that kills the invasive tamarisk tree is threatening the southwestern willow flycatcher, a migratory songbird that nests along Southwest rivers and streams.
The agency in 2001 approved U.S. release of the beetle, native to Asia and the Middle East, to control the Eurasian tamarisk tree, also known as salt cedar, which became established in Southwest river ecosystems after escaping cultivation in the 1800s.
The center cites a 2008 report by the U.S. Fish and Wildlife Service refuting a 2005 biological assessment stating that the insect wouldn't migrate to southern latitudes, and that any habitat change would be gradual. The beetle eats salt cedar leaves, which eventually kills the trees.
The plaintiffs, which include the Maricopa Audubon Society, say the beetles are moving faster than expected, while native flycatcher habitat restoration is not occurring at all due to dams, water diversion and livestock grazing - all causes of the original habitat loss.
The beetles were illegally transported down the Virgin River from Utah to Arizona in 2006 and are defoliating flycatcher nesting areas farther south than expected, resulting in the documented loss of at least one nest so far, the center says.
The beetles are "poised to invade the lower Colorado River and beyond," the group states, which threatens the 1,300 known pairs of birds in the United States.
The southwestern willow flycatcher was listed as an endangered species in 1995. The center also claims that a critical habitat designation for the migratory songbird was slashed for political reasons in 2005.
Plaintiffs, represented by Matt Kenna of the Western Environmental Law Center in Durango, Colo., seek to restart consultation with wildlife agencies over the beetle program.
Read the Top 8
Sign up for the Top 8, a roundup of the day's top stories delivered directly to your inbox Monday through Friday.