2012 Annual Report 1a.Objectives (from AD-416): To investigate the environmental impact of the invasive weed Arundo donax, carrizo gigante, in Mexico, and to evaluate key candidate biological control agents. 1b.Approach (from AD-416): Sites in Mexico with infestations of Arundo donax will be established to determine the impact of this invasive weed on the native flora and water resources. 3.Progress Report: This report documents the successful collaboration with Mexico to rear, release, and evaluate the biological control agents of the invasive weed Arundo donax in the Mexican portion of the bi-national Rio Grande/Rio Bravo River Basin. Collaborators with the Instituto Mexicano Tecnologia del Aguas (IMTA) have documented many serious impacts of A. donax along the rivers and canals of the Rio Grande Basin, northern states of Mexico, and the reservoirs of the central highlands near Mexico City. These impacts include water loss, bank erosion, and reduction in biodiversity. Rearing facilities for the biological control agents were established at IMTA facilities near Cuernavaca, Morelos, and the arundo wasp and arundo scale were transferred from ARS facilities in Texas for rearing and redistribution. The first agent, the arundo wasp, is now established in several States including Tamaulipas, Nuevo Leon, and Chihuahua, which border the Rio Grande. The second agent, the arundo scale, is now established in culture, and releases are planned in Tamaulipas in late 2012. The impacts of A. donax and the benefits of the biological control program in Mexico have been documented in a Spanish language video produced by IMTA. Note: This project was formerly associated with the Weslaco project 6204-22000-022-00D, which expired. This is the final report on this project, which terminates 09/30/2012. This collaboration has been very successful and plans are being initiated to establish a new 5-year agreement.