Keywords: stream pyrethroids Substances: Chlorpyrifos (SBPBAQFWLVIOKP-UHFFFAOYSA-N) Allethrin (ZCVAOQKBXKSDMS-UHFFFAOYSA-N) Cyphenothrin (FJDPATXIBIBRIM-UHFFFAOYSA-N) Chlorpyrifos-methyl (HRBKVYFZANMGRE-UHFFFAOYSA-N)