Keywords: stream pyrethroids Insecticides Substances: Bifenthrin (OXCDWLBJSLVWHB-LKRLXIKPSA-N) Cyfluthrin (OFHFONYRMVKULH-WNYJFNBPSA-N) Transfluthrin (DDVNRFNDOPPVQJ-HQJQHLMTSA-N) Chlorpyrifos-methyl (HRBKVYFZANMGRE-UHFFFAOYSA-N)