LABORATORY AND FIELD EVALUATIONS OF A REPELLENT SOAP CONTAINING DIETHYL TOLUAMIDE (DEET) AND PERMETHRIN AGAINST PHLEBOTOMINE SAND FLIES (DIPTERA, PSYCHODIDAE) IN VALLE DEL CAUCA, COLOMBIA

The repellency and insecticidal efficacy of Nopikex(R), a soap formula tion containing 20% diethyl toluamide and 0.5% permethrin, was evaluat ed against a laboratory colony of phlebotomine sand flies (Lutzomyia l ongipalpis). The repellency of Nopikex soap was also compared with tha t of a placebo soap against another species (Lu. youngi) in a forest n ear Tulua, Valle del Cauca, Colombia. In laboratory trials of the soap , no reduction in repellency was seen 4 hr after application, but with in 8 hr, repellency decreased significantly to 67.0% of the initial va lue (P < 0.05) based on calculations of the coefficient of protection (CP). Under field conditions, the soap gave up to 100% protection imme diately after application, but within 4 hours its CP value had decreas ed to a median value of only 44.3%. The placebo soap was also found to be somewhat repellent when compared with no treatment, giving a media n CP value of 67.7 immediately after application. No significant morta lity was seen in sand flies within 24 hr of exposure to the soap in th e laboratory, even in those that had fed on protected volunteers.