title: Synergy between glyphosate- and cypermethrin-based pesticides during acute exposures in tadpoles of the common South American toad Rhinella arenarum.
abstract: The herbicide glyphosate and the insecticide cypermethrin are key pesticides of modern management in soy and corn cultures. Although these pesticides are likely to co-occur in ephemeral ponds or aquatic systems supporting amphibian wildlife, the toxicological interactions prevailing in mixtures of these two pesticides have been little studied. The current study evaluated the toxicity of equitoxic and non-equitoxic binary mixtures of glyphosate- and cypermethrin-based pesticides to tadpoles of the common South American toad, Rhinella arenarum. Two different combinations of commercial products were tested: glyphosate Glifosato Atanor®+cypermethrin Xiper® and glyphosate Glifoglex®+cypermethrin Glextrin®. When tested individually, the formulations presented the following 96 h-LC50s: Glifosato Atanor® 19.4 mg ae L(-1) and Glifoglex 72.8 mg ae L(-1), Xiper® 6.8 mg L(-1) and Glextrin® 30.2 mg L(-1). Equitoxic and non-equitoxic mixtures were significantly synergic in both combinations of commercial products tested. The magnitude of the synergy (factor by which toxicity differed from concentration addition) was constant at around twofold for all tested proportions of the glyphosate Glifoglex®+cypermethrin Glextrin® mixture; whereas the magnitude of the synergy varied between 4 and 9 times in the glyphosate Glifosato Atanor®+cypermethrin Xiper® mixture. These results call for more research to be promptly undertaken in order to understand the mechanisms behind the synergy observed and to identify and quantify the extent of its environmental impacts.
authors.affiliation: Instituto de Recursos Biológicos, Centro Nacional de Investigaciones Agropecuarias (CNIA), Instituto Nacional de Tecnología Agropecuaria (INTA), Hurlingham, Buenos Aires, Argentina. Electronic address: brodeur.celine@inta.gob.ar.
authors.forename: Julie Céline
authors.initials: JC
authors.lastname: Brodeur
authors.affiliation: Instituto de Recursos Biológicos, Centro Nacional de Investigaciones Agropecuarias (CNIA), Instituto Nacional de Tecnología Agropecuaria (INTA), Hurlingham, Buenos Aires, Argentina.
authors.forename: María Belén
authors.initials: MB
authors.lastname: Poliserpi
authors.affiliation: Instituto de Recursos Biológicos, Centro Nacional de Investigaciones Agropecuarias (CNIA), Instituto Nacional de Tecnología Agropecuaria (INTA), Hurlingham, Buenos Aires, Argentina.
authors.forename: María Florencia
authors.initials: MF
authors.lastname: D'Andrea
authors.affiliation: Instituto de Recursos Biológicos, Centro Nacional de Investigaciones Agropecuarias (CNIA), Instituto Nacional de Tecnología Agropecuaria (INTA), Hurlingham, Buenos Aires, Argentina.
authors.forename: Marisol
authors.initials: M
authors.lastname: Sánchez
mesh_terms: D000818:Animals; D002025:Bufonidae / Q000254:growth & development*; D004357:Drug Synergism; D054750:Ecotoxicology; D005998:Glycine / Q000031:analogs & derivatives* / Q000633:toxicity; D006540:Herbicides / Q000633:toxicity*; D007306:Insecticides / Q000633:toxicity*; D007814:Larva / Q000187:drug effects; D007928:Lethal Dose 50; D011722:Pyrethrins / Q000633:toxicity*; D014874:Water Pollutants, Chemical / Q000633:toxicity*; D000097797:Glyphosate
chemical_list: D005998:Glycine; D006540:Herbicides; D007306:Insecticides; D011722:Pyrethrins; D014874:Water Pollutants, Chemical; D000097797:Glyphosate; C017160:cypermethrin
keywords: Agriculture; Amphibians; Cypermethrin; Glyphosate; Mixtures; Pesticides