Abstract

Neonicotinoids are increasingly applied on trees as protection measure against insect pests. Consequently, neonicotinoids are inevitably transferred into aquatic environments either via spray drift or surface runoff or (due to neonicotinoids' systemic nature) via senescent leaves. There particularly leaf-shredding invertebrates may be exposed to neonicotinoids through both the water phase and the consumption of contaminated leaves. In 7 day bioassays (n = 30), we examined ecotoxicological differences between these two exposure scenarios for an amphipod and an insect nymph with their feeding rate as the response variable. Organisms either experienced waterborne neonicotinoid (i.e., imidacloprid, thiacloprid, and acetamiprid) exposure only or a combined exposure (waterborne and dietary) through both the consumption of contaminated leaves and neonicotinoids leaching from leaves into water. The amphipod (7 day EC(50)s from 0.3 to 8.4/mu g/L) was more sensitive than the insect nymph (7 day EC(50)s from 7.0 to 19.4 mu g/L ). Moreover, for both species, concentration response models derived from water concentrations indicated higher effects under the combined exposure. Together with the observed inability of shredders to avoid neonicotinoid-contaminated leaves, our results emphasize the relevance of dietary exposure (e.g., via leaves) for systemic insecticides. Thus, it would be prudent to consider dietary exposure during the registration of systemic insecticides to safeguard ecosystem integrity.

Published in

Environmental Science and Technology
2017, Volume: 51, number: 10, pages: 5793-5802
Publisher: AMER CHEMICAL SOC

SLU Authors

• Bundschuh, Mirco

  • Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences
    

Associated SLU-program

SLU Plant Protection Network


Sustainable Development Goals

SDG6 Ensure availability and sustainable management of water and sanitation for all
SDG3 Ensure healthy lives and promote well-being for all at all ages


UKÄ Subject classification

Environmental Sciences


Publication identifier

DOI: https://doi.org/10.1021/acs.est.7b00827

Permanent link to this page (URI)

https://res.slu.se/id/publ/83660