The principal objective of the West Umatilla Mosquito Control District and the basic reason for its formation is to provide a comprehensive mosquito control program as the means for preventing the transmission of mosquito borne illnesses through the reduction of its primary vector, the mosquito Culex tarsalis.  Secondary objectives that are also accomplished by the district’s comprehensive program include: freedom from mosquito annoyance, increasing yields in livestock, enjoyment of our yards, patios, parks, golf courses and other outdoor recreational areas.