2009 Annual Report 4.Accomplishments 1. Ultra-low oxygen (ULO) treatment for postharvest control of western flower thrips on lettuce. Presence of western flower thrips on U.S. fresh commodities including lettuce is a major obstacle to their exportation to Taiwan. ARS researchers at Salinas, California developed an efficacious, ultralow oxygen treatment to control the pest on harvested lettuce. A 3-day storage period immediately prior to ultralow oxygen treatment of different lettuce cultivars achieved complete control of thrips without any negative effects on lettuce quality in a pallet scale study. The research reduced overall time needed to complete ULO treatment and thereby made the ULO treatment more practical for commercial adaptation. 2. Ultra-low oxygen treatment for control of Vine mealybug on grape rootstocks. Vine mealybug, a major pest of vineyards, is difficult to control on grape rootstocks with foliar pesticides and the currently used method of hot water dipping of dormant rootstocks after harvest is labor intensive. ARS researchers at Salinas, California successfully developed an efficacious, ultralow oxygen treatment to solve this vine mealybug problem. The pest was controlled by storing rootstocks with vine mealybug under ultralow oxygen treatment for 3 or 4 days at 25 or 15°C, respectively. The treatments caused 100% mortality of all life stages of vine mealybug and had no negative effects on rootstock growth. The ULO treatments provide a safe, effective, and economical alternative to the hot water immersion treatment for control of vine mealybug. 6.Technology Transfer Number of Invention Disclosures Submitted 1 Number of Other Technology Transfer 2