Survival of head lice exposed to filter papers treated with permethrin

Date when lice collectedTreatment and doseTotal No of lice collectedAble to feed after 24hSurviving >48 h
Oct 1994Permethrin 6.3 μg/cm25517 (31)15 (27)
Jan 1995Untreated3114 (45)14 (45)
Jan 1995Permethrin 6.3 μg/cm26935 (51)33 (48)
Mar 1995Untreated2712 (44)12 (44)
Mar 1995Permethrin 15.8 μg/cm23114 (45)12 (39)