Keywords: stream pesticides pyrethroids Substances: Bifenthrin (OXCDWLBJSLVWHB-LKRLXIKPSA-N) Chlorpyrifos (SBPBAQFWLVIOKP-UHFFFAOYSA-N) Deltamethrin (OWZREIFADZCYQD-NSHGMRRFSA-N) Empenthrin (YUGWDVYLFSETPE-JLHYYAGUSA-N) Cyfluthrin (OFHFONYRMVKULH-WNYJFNBPSA-N)