Effects of glyphosate-based herbicides on survival, development, growth and sex ratios of wood frog (Lithobates sylvaticus) tadpoles. II: Agriculturally relevant exposures to Roundup WeatherMax® and Vision® under laboratory conditions

The response of amphibian larvae to exposure to a glyphosate-based herbicide (Roundup WeatherMax) and nutrient enrichment in an ecosystem experiment

“…The general lack of herbicide induced mortality contrasts with the majority of previously published studies conducted on other glyphosate-based herbicide formulations (Edginton et al, 2004;Howe et al, 2004;Relyea, 2004Relyea, , 2005 and laboratory studies conducted on Roundup WeatherMax (Fuentes et al, 2011;Williams and Semlitsch, 2010;Lanctôt et al, 2014). All of which found adverse effects on survival in the range of the high initial exposure concentrations used in this study.…”

Is there a link between autism and glyphosate-formulated herbicides?

“…In tadpoles, glyphosate-formulated herbicide exposure reduced the normal increase of mRNA for Thyroid Receptor beta during developmental Gosner stages Gs37-42 [12]. However, at Gs42, only males demonstrated this effect, suggesting that females are hormonally protected in utero.…”

“…In fact, glyphosate-formulated herbicide exposure alters gene expression for thyroid hormone receptor beta and deiodinase enzyme, with different alterations depending on stage/gender [12]. Specifically, in tadpoles, exposure to glyphosate-formulated herbicide is linked to an increase in expression of thyroid receptor beta in brain [13], presumably as a defense mechanism in the face of low T4.…”

Land-use changes and agriculture in the tropics: pesticides as an overlooked threat to wildlife

“…The continuous loss of forest in favour of agricultural land is bringing to collapse populations of many species potentially important for pest control. Moreover, detrimental effects of pesticides can also occur at doses lower than maximal rates used in agriculture or for new pesticide formulations that are thought to be less toxic than old formulations (Lanctôt et al 2014;NavarroMartín et al 2014). We should also not loss sight of the fact that research in temperate regions showed that taxa or different life-cycle stages differ in sensitivity to pesticides (Relyea 2005).…”

“…Direct effects of chronic exposure to pesticides include endocrine disruption, immune-and neuro-toxicity or altered metabolism (Köhler and Triebskorn 2013). These physiological effects of pesticides translate in altered growth and development, abnormal behaviour, decreased survival or increased local extinction in both terrestrial and aquatic species (Relyea 2005;Lanctôt et al 2014). Research has also shown drastic indirect effects of pesticides on wildlife, acting predominantly via reduction in food supplies or altered ecosystem function (Ogada and Kibuthu 2009;Köhler and Triebskorn 2013).…”