Russian Wheat Aphid, Diuraphis noxia (Mordvillko): A New Insect Pest of Small Grains in Arizona

Russian wheat aphid infestations were generally very light in Arizona in the spring of 1987. In the Florence /Coolidge area of Pinal County, only one of eight fields was lightly RWAinfested. Most infestations were limited to occasional tillers within moisture -stressed areas of fields, or they were along field margins in plants not reached by irrigation. At the Maricopa Agricultural Center, limitedirrigation barley was more heavily infested than were adjacent fullyirrigated small grains.