The Tamarisk Coalition’s latest survey maps for work done over the summer of 2015 show that the beetle has now spread along the entire Rio Grande in New Mexico. The light blue dots are areas where the beetle showed up this year:
The beetle was originally introduced in Colorado and Utah as an experiment in invasive species control, an attempt to halt the spread of the Eurasian tamarisk tree, seen (rightly or wrongly, the science is mixed) as a water hog. But the bugs quickly spread farther than expected, and as you can see they’re now pretty widespread across the West. (Background here.)
Notice the populations also showing up on the Montana-Wyoming border. What’s up with that?