Combate sistemático de formigas-cortadeiras com iscas granuladas, em eucaliptais com cultivo mínimo

摘要

The efficiency of a systematic application of baits against leaf-cutting ants was evaluated in a eucalypus plantation under a minimum cultivation system, in areas owned by Celulose Nipo-Brasileira S.A. (CENIBRA), in Belo Oriente, Minas Gerais, Brazil, from September to December 1996. Treatments consisted of applying a granulated bait with sulfluramide (0.3%) in a systematic manner in bulk and plastic bags at a dose of five grams every 6 m2 (T1) and 10 grams at each 12 m2 (T2). Mortality of colonies of leaf-cutting ants was evaluated 30 days after bait application. A. maximum of 396.3; 285.2; 59.3; 55.6; 29.6 and 14.8 colonies of Mycocepurus goeldii, Sericomyrmex sp., Acromyrmex subterraneus molestans, Atta spp., Acromyrmex balzani and Acromyrmex niger (Hymenoptera: Formicidae), respectively, was found per hectare. The efficiency of this granulated bait, applied in a systematic manner, varied with the method and species of leaf-cutting ants. Higher efficiency was obtained for A. subterraneus molestans, with 69.2% of dead colonies with the bait applied in bulk and 62.5% when it was applied in plastic bags. This shows that bait distribution in the eucalyptus plantation was performed at a larger spacing than the foraging area of leaf-cutting ants and/or that the dose was insufficient.