Iscas biológicas para controle de formigas cortadeiras (Hymenoptera: Formicidae)

Abstract

Leaf-cutter ants cause great loss to forest and agricultural crops, by causing significant damage in plantations. Nowadays, the chemical method is the best alternative to control these ants. The most common form of this method is the granulated baits that contain sulfuramide. Research that aim at the use of biological baits formulated with entomopathogenic fungi could come to replace this method. The objective of this study was to develop and test biological baits using entomopathogenic fungi. The methodology was developed on the UFRB campus in the city of Cruz das Almas, with isolated fungi, vegetative growth and conidia production in culture medium (PDA), isolation of conidia in the body of insects, preparation of suspensions concentrated to 1,0 x 107 and 1,0 x 108 conidia /mL for each fungus. For the pathogenicity test, large workers were collected from Atta laevigata colonies. In the manufacturing of baits, plant materials such as “angico vermelho” leaves (Anadenanthera macrocarpa (Benth.) Brenan), acalypha wilkesiana and roses were collected, as well as orange and flour wastes. Once ready, an evaluation of attractiveness and carrying of the baits by the workers was performed, recording the time they spent. The isolated Aspergillus flavus and Trichoderma harzianum were pathogenic to the A. laevigata in laboratory. All insecticide baits tested present equal attractiveness to the A. laevigata. The average carrying time was 0,67 minutes and the “angico-vermelho” presented the lowest transportation time. The design was in randomized blocks and the data was submitted to analysis of variance by the Tukey’s test at 5% probability.