Although many insecticides have been tested as baits against leaf cutting ants, the market was dominated by those with dodecachlor. This compound was banned and the new baits for these pests have either sulfluramid or chlorpirifos. The objective of this work was to test the Landrin-F (chlorpirifos 0.45%) bait against the leaf cutting ant Atta laevigata (F. Smith, 1858) (Hymenoptera: Formicidae) compared to Mirex-S (sulfluramid 0.3%) bait. Treatments used were: application of 30 to 120 grams of the Landrin-F bait for each ant hole; application of 8g/m² of ant nest of Landrin-F bait; application of 8g/m² of ant nest of Mirex-S bait and; control, no bait was applied. After 24 and 48 hours the transport and refusal of the baits were evaluated, and after 7, 15, 30, 60, 90, 120, 150, 180 and 210 days ant colonies activity was evaluated. Ant colonies were excavated after 180 days and its activity was evaluated after 210 days. The application of Landrin-F bait based in active ant holes increased the amount of bait in relation to bait quantity applied per square meter of ant colony. Since the efficiency of the Landrin-F bait was similar in both methodologies it is recomended that this bait should be applied at the dosage of 8 g/m² of ant colony to control A. laevigata.
chemical control; leaf-cutting ants; Eucalyptus
