Use of alternatives to PFOS, its salts and PFOSF for the control of leaf-cutting ants Atta and Acromyrmex

Abstract

Several biological, chemical, cultural and mechanical methods have been studied for the control of leaf-cutting ants due to their economic importance in forestry, agriculture and pastures. Applied biological methods such as manipulating predators, parasitoids and microorganisms; conservative control, non-preferred plants (resistents), extracts of toxic plants or active ingredients of botanical origin and cultural methods; have been unsatisfactory with inconsistent results. With the development of synthetic insecticides, chemical methods have been effectively used to control these ants. Currently, the use of toxic bait with active ingredient with delayed action on a wide range of concentrations, is being employed and it's sufficient, viable and efficient. However,it is extremely time consuming and difficult to find new active ingredients that are viable and efficient because of the great limitations associated with finding the essential features desired of the active ingredient (the action by ingestion, odourlessness and non-repellant, delayed toxic action, lethality at low concentrations and paralyses of plant cutting activities in the first days after application). Chemical control with toxic baits is still the only method that is technologically available to control leaf-cutting ants with technical, economic and operational viability. Beyond efficiency, chemical control has great advantages over other methods such as low cost, high performance and low hazard to humans and the environment. Sulfluramid is among the active ingredients currently registered in Brazil; the only one that has all the characteristics necessary for proper functioning of toxic bait. Therefore, maintaining this active ingredient is essential; at the risk of a dangerous set back in the control of leaf-cutting ants such as pest population growth and huge losses to the Brazilian agribusiness, if sulfluramid production is discontinued. In the light of current knowledge, it is believed that the future in the control of leafcutting ants remains exclusively chemical and the commercial formulation is toxic bait, because of the limitations of other formulations.