From the Tamarisk Coalition website:
Each year, with the help of numerous partners across eleven states and Mexico, TC produces an annual distribution map that notes the presence and absence of Diorhabda spp. from sampling sites across the west. These data in no way represent all locations where the tamarisk beetle may exist, but give a broad perspective of beetle dispersal, providing land managers with information that may help with their integrated pest management plans, restoration strategies, and funding opportunities. If you would like to participate in the program, or help fill any “gaps” you may see in current data on the map, please visit our tamarisk beetle monitoring program page.
For 2014, TC would like to thank more than 30 partners directly involved in providing this year’s data, and more than 60 that have provided data during the span of TC’s involvement in tracking beetle locations across the west. This year showed rapid population expansion in Kansas, Oklahoma, and eastern New Mexico, with a slowing of spread along the Rio Grande in New Mexico, and a “stall” in southern Arizona. This decreased expansion, as compared to movement the last few years, is most likely indicative of the Northern Tamarisk Beetle (Diorhabda carinulata) reaching the southern limits of its physiological constraints along the Colorado, Little Colorado, and Rio Grande. There are three other species of tamarisk beetle in North America, and this year was the first time that all four species were recorded in a single state, New Mexico.
The production of the Annual Tamarisk Beetle Distribution Map is generously funded by a grant from the Walton Family Foundation.
More tamarisk control coverage here.