title: Do insect repellents induce drift behaviour in aquatic non-target organisms?
abstract: Synthetic insect repellents are compounds applied to surfaces to discourage insects, mainly mosquitoes, from landing on those surfaces. As some of these repellents have repeatedly been detected in surface waters at significant concentrations, they may also exert repellent effects on aquatic non-target organisms. In running water systems, aquatic invertebrates actively enter downstream drift in order to avoid unfavourable environmental conditions. We thus tested the hypothesis that the widely used insect repellents DEET (N,N-Diethyl-m-toluamide), EBAAP (3-[N-butyl-N-acetyl]-aminopropionic acid ethyl ester) and Icaridin (1-piperidinecarboxylic acid 2-(2-hydroxyethyl)-1-methylpropyl ester) induce downstream drift behaviour in the aquatic invertebrates Gammarus pulex (Crustacea, Amphipoda) and Cloeon dipterum (Insecta, Ephemeroptera), using a laboratory-scale drift assay. We found no clear increase in the drift behaviour of both invertebrate species across a concentration gradient of eight orders of magnitude and even beyond maximum environmental concentrations for any of the three repellents. We found no evidence for a direct drift-inducing activity of insect repellents on aquatic non-target organisms.
authors.affiliation: University of Cologne, Cologne Biocenter, Workgroup Aquatic Chemical Ecology, Zülpicher Strasse 47b, 50674 Koeln, Germany. Electronic address: fink@limno.net.
authors.forename: Patrick
authors.initials: P
authors.lastname: Fink
authors.affiliation: University of Cologne, Cologne Biocenter, Workgroup Aquatic Chemical Ecology, Zülpicher Strasse 47b, 50674 Koeln, Germany.
authors.forename: Jana
authors.initials: J
authors.lastname: Moelzner
authors.affiliation: German Federal Environment Agency (Umweltbundesamt), Schichauweg 58, 12307 Berlin, Germany.
authors.forename: Ruediger
authors.initials: R
authors.lastname: Berghahn
authors.affiliation: University of Cologne, Cologne Biocenter, Workgroup Aquatic Chemical Ecology, Zülpicher Strasse 47b, 50674 Koeln, Germany.
authors.forename: Eric
authors.initials: E
authors.lastname: von Elert
mesh_terms: D000818:Animals; D059001:Aquatic Organisms; D003671:DEET; D007302:Insect Repellents; D014867:Water
chemical_list: D007302:Insect Repellents; D014867:Water; D003671:DEET
keywords: Bayrepel; DEET; Drift; EBAAP; Icaridin; Infochemicals