A recent article in one of our papers was about a tamarisk beetle that kills the tamarisk trees that have invaded the waterways of the southwestern United States, choked out native vegetation and dried up many water ways.



The beetles, no bigger than pencil erasers, assault tamarisk, also known as salt cedar. The bushy tree sucks up hundreds of billions of gallons of water a year and crowds out native plants along creeks and rivers. It can grow up to a foot a month, to a height of 30 feet. The leaves secrete salt, making nothing else grow on the ground below.

Tamarisk was imported from Asia in the early 1800s as a garden ornamental and for windbreaks and other soil-stabilization projects. Its feathery pink-and white blossoms are common in creek beds and streams in many semi-arid parts of the West.

Mature trees produce up to 500,000 seeds a year. The species now infests springs, ditches and wetlands in more than a dozen western states. It has taken root in more than 1.5 million acres from Mexico to Canada and from the Midwest to the Pacific.

One article I read acknowledged that it may turn out the beetles could evolve and start eating other vegetation once the tamarisks are gone, but state weed control people have not seen any sign of this - if the beetles hatch too early for there to be tamarisk leaves to eat, they just die off, don't eat anything else.

If successful, the beetle assault will take years to stop the spread of tamarisk, let alone allow native plants to re-establish.

Interesting point, these beetles can only be planted on private or state owned property - of course they'll spread to Bureau of Land Management property and nothing is being done to prevent that, but the way the laws are currently, they can't plant them on national (BLM) property.

From personal experience, I have seen the small rivers around my uncle's trading post totally dry up after the take-over of the river banks by the tamarisks, so I am rooting for the beetles.

Another invasive tree that sucks up water and drives out native species is the Russian Olive, which is banned by some cities in Colorado.