The Effect of Cypermethrin, Chlorpyrifos, and Glyphosate Active Ingredients and Formulations on Daphnia magna (Straus)

Abstract

Acute effects of active ingredients (a.i.) andformulations (F) of widely used pesticides were assessedby means of the Daphnia magna toxicity test. Studiedpesticides were the insecticides, cypermethrin and chlorpyrifos,and the herbicide, glyphosate. Results were analyzedand compared according to statistical endpoints(LCx) and log-probit regressions of toxicity data. Thepotency of acute toxicity followed the order: chlorpyrifosF[chlorpyrifos a.i.[cypermethrin F[cypermethrina.i. glyphosate F[glyphosate a.i. Three to five ordersof magnitude differences between the toxicity (lg/L to mg/L) of insecticides and the herbicide were observed. Apairwise comparison between a.i. and F indicated that allformulations were more potent. Additionally, for the caseof glyphosate, evidence suggests that the adjuvant contributesto formulation toxicity rather than to theenhancement of a.i. potency.