CLARKDALE, Ariz. (AP) - Tiny beetles brought to the U.S. to devour invasive tamarisk trees are now in a central Arizona riverbank.
Their arrival this summer at the Verde River is no surprise.
But it's further proof the tamarisk leaf beetles are spreading faster than once anticipated and eventually could be throughout the entire Southwest United States.
Scientists say tamarisk beetles in the thousands can kill entire trees, also known as salt cedars. That raises the risk of wildfire and allows less time to replace the invasive trees with native cottonwoods and willows where an endangered songbird makes its nest.
Their numbers are low at the Verde River. The bigger concern is the beetles reaching other rivers in Arizona where more Southwestern willow flycatchers live.
As the beetles munch through tamarisk leaves, the songbird loses cover from predators.