Southern Fire Ant (Hymenoptera: Formicidae) Damage to Harvested Almonds in California

Individual Solenopsis xyloni McCook colonies were identified in California almond orchards; additional colonies were excluded for a radius of 9 m around the central colony. Each plot was uniformly covered with newly harvested almonds. Data showed that damage increased proportionally to both increasing density of colonies and the number of days that nuts remained on the ground. Entrances to the colonies moved within a limited area during a 22-day period following nut placement. S. xyloni were most active in the morning and before sunset. When diazinon 14G was applied to control the ants, simulated sprinkler irrigation immediately following application increased the effectiveness of the treatment.