caa a22 4500 386361754 CHVBK 20180307111918.0 cr unu---uuuuu 161130e198912 xx s 000 0 eng 10.4039/Ent1211077-12 doi S0008347X0003594X pii (NATIONALLICENCE)cambridge-10.4039/Ent1211077-12 DRIFT OF AQUATIC INSECTS FOLLOWING METHOXYCHLOR TREATMENT OF THE SASKATCHEWAN RIVER SYSTEM [Elektronische Daten] Drift of aquatic insects was compared at three sites downstream (21, 38, and 107 km) from methoxychlor treatment (0.3 mg. L−1 for 15 min) of the North Saskatchewan River, relative to an upstream untreated site. Species of Diptera (Simuliidae), Ephemeroptera (Baetidae, Heptageniidae, Ephemerellidae, Ametropodidae, Metretopodidae, and Tricorythidae), Plecoptera (Perlodidae and Chloroperlidae), Trichoptera (Hydropsychidae and Hydroptilidae), and Hemiptera (Corixidae) were studied. Drift responses differed depending on species, distance from the injection site, and time after methoxychlor injection. Exposure to methoxychlor initiated catastrophic drift of aquatic insects at all downstream sites. Of 22 species compared before treatment and following methoxychlor injection, post-treatment drift of 17, 21, and 13 species significantly exceeded pre-treatment drift at the km 21, 38, and 107 sites, respectively. Methoxychlor treatment initiated or increased drift of several normally non-drifting species. Similar drift patterns were observed among closely related taxa during the catastrophic phase. For all species studied, comparisons of 24-h drift densities between days preceding and following the catastrophic phase of treatment indicated significant post-treatment drift density increases or decreases at one or more of the downstream sites, but not at the untreated site. Species were classified according to their drift responses to methoxychlor treatment. Factors that may have caused different drift responses among species are discussed. Copyright © Entomological Society of Canada 1989 Dosdall Lloyd M. Department of Biology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada S7N 0W0 Lehmkuhl Dennis M. Department of Biology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada S7N 0W0 The Canadian Entomologist Cambridge University Press 121/12(1989-12), 1077-1096 0008-347X 121:12<1077 1989 121 TCE https://doi.org/10.4039/Ent1211077-12 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.4039/Ent1211077-12 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Dosdall Lloyd M. Department of Biology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada S7N 0W0 NATIONALLICENCE 700 1- Lehmkuhl Dennis M. Department of Biology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada S7N 0W0 NATIONALLICENCE 773 0- The Canadian Entomologist Cambridge University Press 121/12(1989-12), 1077-1096 0008-347X 121:12<1077 1989 121 TCE CC0 http://creativecommons.org/publicdomain/zero/1.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-cambridge