Abstract: Methods for disinfesting insect pests such as the Mexican fruit fly in citrus fruit such as grapefruit with minimal adverse effect on fruit quality include placing and maintaining such fruit for a time period of about 15 to about 21 days at a temperature of about 14° to 18° C. and in a gaseous mixture that includes not more than about 0.05% oxygen by volume, a balance nitrogen or up to 20% carbon dioxide in combination with nitrogen.