Do the neonicotinoid insecticide imidacloprid affect the aquatic macrophyte Myriophyllum quitense? A multiple biomarker study.

ITURBURU F.G.; GARANZINI D.S.; MENONE M.L.

Wiscosin, Madison.

Encuentro; 7th SETAC Young Environmental Scientists Meeting.; 2018

SETAC

The neonicotinoid imidacloprid (IMI) is a systemicinsecticide widely used on crop protection. This hydrophyllic compound is underreview by different government agencies because the unexpected effects of IMI onnon-target organisms, mainly on invertebrates. Besides the toxicity on theseorganisms, other components of the aquatic community could be affected, likefish or macrophytes. In this context, the objective of this work was toevaluate the effects of IMI on the macrophyte Myriophyllum quitense, both on conventional parameters (growth) ason sublethal biochemical biomarkers related with oxidative stress and photosyntheticpigments concentration. For this purpose, two bioassays were performed. Onetesting biomarkers in plants exposed to 1, 10, 100 and 1000 μg/L IMIduring  48 h and the other using 10, 100,1000, 10000 and 20000 µg/L IMI and 14 days. At 48 h there was a decrease of chlorophyllA and B concentrations as well as an increase of H2O2 andlipid peroxidation in plants exposed to low IMI concentrations. These effectsseem not to be kept on time because after 14 days of exposure, plant growth wasnot affected by any IMI concentration, and there was an increase of carotenoidsand chlorophylls A and B concentrations, but only at the highest assayedconcentration (20000 ug/L IMI). The results showed that after a short termexposure to environmentally relevant IMI concentrations, sublethal effectscould be produced in M. quitense,while a longer exposure time seems not to affect plant growth.