Keywords: stream pesticides pyrethroids Substances: Bifenthrin (OXCDWLBJSLVWHB-LKRLXIKPSA-N) Cyphenothrin (FJDPATXIBIBRIM-UHFFFAOYSA-N) Cyfluthrin (OFHFONYRMVKULH-WNYJFNBPSA-N) Cypermethrin (KAATUXNTWXVJKI-UHFFFAOYSA-N)