IJRES 3 (2016) 11-92 ISSN 2059-1977 Use of alternatives to PFOS, its salts and PFOSF for the control of leaf-cutting ants Atta and Acromyrmex Júlio Sérgio de Britto1, Luiz Carlos Forti2*, Marco Antonio de Oliveira3, Ronald Zanetti4, Carlos Frederico Wilcken2, José Cola Zanuncio3, Alci Enimar Loeck5, Nádia Caldato2, Nilson Satoru Nagamoto2, Pedro Guilherme Lemes3 and Roberto da Silva Camargo2 1Ministry of Agriculture, Livestock and Supply (MAPA), Esplanada dos Ministérios, Bloco D, Brasília/DF, 70043-900, Brazil. 2Departamento de Proteção Vegetal, Faculdade de Ciências Agronômicas/UNESP, 18603-970, Botucatu, São Paulo State, Brazil. 3Departamento de Entomologia, Universidade Federal de Viçosa, 36571-000, Viçosa, Minas Gerais State, Brazil. 4Departamento de Entomologia, Universidade Federal de Lavras, Campus Universitário, s/n, Campus Universitário, 37200-000,Lavras, Minas Gerais State, Brazil. 5Departamento de Fitossanidade, FAEM,Universidade Federal de Pelotas, 96010-900, Pelotas, Rio Grande do Sul State, Brazil. Article History ABSTRACT Received 07 March, 2016 Several biological, chemical, cultural and mechanical methods have been Received in revised form 23 studied for the control of leaf-cutting ants due to their economic importance in March, 2016 Accepted 28 March, 2016 forestry, agriculture and pastures. Applied biological methods such as manipulating predators, parasitoids and microorganisms; conservative control, Keywords: non-preferred plants (resistents), extracts of toxic plants or active ingredients of Acromyrmex, botanical origin and cultural methods; have been unsatisfactory with Atta, inconsistent results. With the development of synthetic insecticides, chemical Integrated Pest methods have been effectively used to control these ants. Currently, the use of Management, toxic bait with active ingredient with delayed action on a wide range of Toxic plants. 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 leaf- Article Type: cutting ants remains exclusively chemical and the commercial formulation is Review toxic bait, because of the limitations of other formulations. ©2016 BluePen Journals Ltd. All rights reserved Int. J. Res. Environ. Stud. 12 INTRODUCTION Atta nest causes a drop in productivity of 3.2 t/ha of sugar cane, corresponding to 5.3% of the productivity (Precetti The leaf-cutting ants belong to the family Formicidae, et al., 1988). subfamily Myrmicinae, tribe Attini known as saúvas In the agricultural commodity chains such as grains, (genus Atta) and ―quenquéns” (genus Acromyrmex). fruits and others, big losses in agricultural productivity are They are cited as the main pest of forest plantations, added, since in these cultures the occurrence of leaf- agriculture and livestock, due to the damage they cause, cutting ants is very expressive. For all these cultures, it as well as their wide occurrence in those areas. can be said that when the plants are young, losses can Concerns about damage by leaf-cutting ants have been reach 100% (Forti and Boaretto, 1997). around since the discovery of Brazil and in some States The management of leaf-cutting ants is essential for legal acts were created for the management of these Brazilian agribusiness, as these can cause great damage pests (Mariconi, 1970). Since then, there have been to agricultural and forest cultivations, bringing huge various attempts to estimate the damage posed by the losses to the country. pests in various agro-ecosystems. Problems with leaf-cutting ants have led to the The damage caused by the Atta sexdens rubropilosa development of mechanical, cultural, biological and activity (Forel, 1908) at a density of 4 colonies/ha was chemical control methods for the integrated management estimated at 14% for eucalyptus plantations and 14.5% of this pest since the 50s. The previous control prevents for pine production (Amante, 1967c). damage to crops, reduces the amount of applied Eucalyptus trees die after 3 consecutive defoliations insecticide during the forthcoming years, can prevent the caused by saúvas and the loss of Eucalyptus stumps occurrence and re-infestation, reducing damage, and the may reach up to 30% in areas with 200 colonies of environmental impact of a later combat. quenquéns per hectare on average (Mendes Filho, Cultural control with ―resistant plants‖ and applied 1979). biological, manipulating predators, parasitoids, and Defoliation caused by leaf-cutting ants in Pinus taeda microorganisms have produced poor and inconsistent has shown that this species seedlings with 100% of results without indication of technical, economic, and defoliation at 30 days of age suffered losses of 13.3% in operational feasibility. There are basic studies under height and 20% in diameter in comparison to plants development at research centers and universities which were not attacked, one year after the defoliation assessing biological products such as entomopathogenic (Reis Filho et al., 2011). Moreover, the complete fungi, as well as natural products such as plant extracts, defoliation of Eucalyptus grandis and P. taeda at one for the control of leaf-cutting ants. The results, however, month of age caused mortality from 10 to 25% for each have been inconsistent, showing technical, economic and species, respectively. The attack of the Acromyrmex operational infeasibility (Forti and Boarettto, 1997; genus ants in P. taeda plants reduced the increase in Moreira et al., 2004a). diameter and height during the first two years of planting With the development of synthetic insecticides, (Cantarelli et al., 2008). chemical methods have been effectively used to control Amante (1967a, b), using unknown methods, Atta and Acromyrmex (Mariconi, 1970; Cherrett, 1986a; concluded that Atta capiguara consumes a tremendous Camargo, 2007; Nagamoto et al., 2007). Chemical amount of 255-639 kg of dry matter/colony/year of control is the only one which presents the available Gramineae, which can be converted into losses of 512 to technology for practical use with leaf-cutting ants control. 870 thousand head of cattle per year. These data were Toxic bait represent the only method that offers technical, reanalyzed by Fowler et al. (1990), whose losses can be economic and operational feasibility with the control of estimated between 30 and 150 kg of dry leaf-cutting ants, and consists of a mixture of attractive matter/colony/year. For Atta vollenweideri, which is also a (usually orange pulp and vegetable oil) and an active grass-cutting ant, it consumes 90 to 250 kg/colony/year ingredient (insecticide), in pellet form. They are highly (Fowler et al., 1986). In general, A. capiguara does not efficient, presenting huge advantages over other reduce the number of cattle by more than 30% (Amante, methods, low cost, high performance, and low hazard to 1967a, b). humans and the environment. The ants carry the bait to The economic losses caused by grass-cutting ants their nests (Lima et al., 2003; Teixeira and Santos, 2008). beyond go beyond the grass consumption, and such as: Baits can be used in nests of any size (Zanetti et al., loss of productive pasture surface, accidents with animals 2002). Toxic baits of leaf-cutting ants slowly paralyze the and farm machinery, weed proliferation, loss of soil cutting activity in a few days (Zanetti et al., 2004). fertility and land value, etc. (Fowler et al., 1986). An adult Sulfluramid, generally used as the active ingredient of toxic baits, presents full efficiency in the control of all species of leaf-cutting ants and grass-cutting ants, presenting technical feasibility, excellent cost/effective- *Corresponding author. E-mail: [email protected]. ness, availability, and affordability, matching the de_Britto_et_al. 13 Toxicological Class IV - lightly toxic. The forestry industry which gathers ants with the ability to cultivate fungi and has been a pioneer in the replacement of dodecachlor- use them as food for their larvae (Silva et al., 2003a). It is based baits by the sulfluramid-based ones (Zanuncio et estimated that the origin of the habit of cultivating fungi al., 1992, 1993). occurred about 50 million years ago, period during which In order to meet the request made by Decision SC-6/7, the ancestor of the tribe changed from a hunting behavior item 5, letter C of UNEP/POPS/COP.6/33,