title: Contact toxicity of permethrin-impregnated military uniforms to Culex pipiens (Diptera:Culicidae) and Phlebotomus papatasi (Diptera: Psychodidae): effects of laundering and time of exposure.
abstract: The effects of laundering and time of exposure on the insecticidal activity of military uniform fabric impregnated with permethrin at 0.125 mg active ingredient (AI)/cm2 are reported from susceptibility tests with laboratory-reared mosquitoes, Culex pipiens, and sand flies, Phlebotomus papatasi. Knockdown/mortality resulting from exposure of groups of female insects for periods of 1, 3, 5, 7, and 10 min was recorded and compared among 5 different treatment/wash groups (untreated/unwashed, treated/unwashed, treated/1-wash, treated/2-wash, treated/3-wash). Laundering was by machine washing with detergent and warm water followed by hot-air machine drying. Post-exposure assessments at intervals from 0 to 60 min and at 24 h showed that knockdown for each exposure time and wash group was initially low but increased steadily during the first hour post-exposure. Sand flies were less sensitive than mosquitoes to knockdown during the first 60 min after contact with treated/unwashed fabric; however, 24-h mortality rates for sand flies were higher as compared with mosquitoes. The permethrin remaining after a 3rd wash had little knockdown effect on mosquitoes but was toxic to sand flies at each of the 5 exposure times. Significant reductions in the knockdown effectiveness of permethrin-treated fabric to mosquitoes and sand flies was associated with single and repeated washings of the fabric.
authors.affiliation: Department of Entomology, Faculty of Science, Ain Shams University, Abassia, Cairo, Egypt.
authors.forename: D J
authors.initials: DJ
authors.lastname: Fryauff
authors.forename: M A
authors.initials: MA
authors.lastname: Shoukry
authors.forename: H A
authors.initials: HA
authors.lastname: Hanafi
authors.forename: Y M
authors.initials: YM
authors.lastname: Choi
authors.forename: K E
authors.initials: KE
authors.lastname: Kamel
authors.forename: C E
authors.initials: CE
authors.lastname: Schreck
mesh_terms: D000818:Animals; D003020:Clothing; D003465:Culex; D005260:Female; D007300:Insect Control; D007306:Insecticides; D007846:Laundering; D008889:Military Personnel; D009032:Mosquito Control; D026023:Permethrin; D011576:Psychodidae; D011722:Pyrethrins; D013997:Time Factors
chemical_list: D007306:Insecticides; D011722:Pyrethrins; D026023:Permethrin