title: Realistic pesticide exposure through water and food amplifies long-term effects in a Limnephilid caddisfly.
abstract: Pesticides are increasingly recognized as relevant stressors in stream ecosystems. Stream biota is exposed to pesticides with low water solubility, e.g. pyrethroid insecticides, via water, habitat, and food. However, long-term effects of simultaneous exposure pathways are unknown. In this context, we conducted a microcosm experiment with the caddisfly Anabolia nervosa exposing the larvae to the pyrethroid insecticide esfenvalerate (EFV) at 0.1 and 1.0μgL-1via (i) water, (ii) food or a (iii) combination of water and food. Combined exposure through water and food significantly reduced emergence by 60% and significantly postponed emergence timing at the highest EFV level, whereas none of the single-phase exposures showed significant effects. Moreover, our study revealed that successfully emerged females from the highest biphasic treatment level were characterised by altered composition of storage lipids indicative of reduced energy reserves. Consequently, a realistic test scenario that represents simultaneous exposure of organisms and their food may reveal substantially increased long term effects of pyrethroids when compared with current ecological risk assessment applying only single phase exposure. We recommend that relevant concurrent exposure routes of pesticides should be considered in order to derive realistic regulatory acceptable concentrations of pesticides.
authors.affiliation: UFZ, Helmholtz Center for Environmental Research, Department System-Ecotoxicology, Permoserstrasse 15, 04318 Leipzig, Germany; Aarhus University, Dept. of Bioscience, Vejlsoevej 25, 8600 Silkeborg, Denmark. Electronic address: jr@bios.au.dk.
authors.forename: Jes Jessen
authors.initials: JJ
authors.lastname: Rasmussen
authors.affiliation: UFZ, Helmholtz Center for Environmental Research, Department System-Ecotoxicology, Permoserstrasse 15, 04318 Leipzig, Germany.
authors.forename: Lena
authors.initials: L
authors.lastname: Reiber
authors.affiliation: Aarhus University, Dept. of Bioscience, Vejlsoevej 25, 8600 Silkeborg, Denmark.
authors.forename: Martin
authors.initials: M
authors.lastname: Holmstrup
authors.affiliation: UFZ, Helmholtz Center for Environmental Research, Department System-Ecotoxicology, Permoserstrasse 15, 04318 Leipzig, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Liess
mesh_terms: D000818:Animals; D020387:Food Chain; D007306:Insecticides / Q000009:adverse effects*; D007814:Larva / Q000187:drug effects; D000074746:Neoptera / Q000187:drug effects*; D011722:Pyrethrins / Q000009:adverse effects; D014867:Water; D014874:Water Pollutants, Chemical / Q000009:adverse effects*
chemical_list: D007306:Insecticides; D011722:Pyrethrins; D014874:Water Pollutants, Chemical; D014867:Water
keywords: Multiple exposure; Population effects; Pyrethroids; Risk assessment; Streams; Trichoptera