A new eriophyid mite ( Aceria neocynodonis Keifer) was discovered infesting a Bermuda grass lawn at Phoenix, Arizona in August 1959. Later in 1959 the new mite was also found at Yuma and Tucson causing extensive damage. Other specimens were identified from Imperial County and near Los Angeles, California. A typical rosetting and tufting of the growth caused by the shortening of the internodes occurs. Eventually lawns are thinned out where the plants are killed. Initial chemical control measures indicated that satisfactory results ean be accomplished with Diazinon® ( O,O -diethyl O -(2-isopropyl-6-methyl-4-pyrimidinyl) thiophosphate) spray or dusting sulfur 325-mesh.