Pre-treating House Flies with Synergists Before Applying Pyrethrum Sprays

Abstract

A high knock-down of house flies resulted when a 0.1% pyrethrin spray was applied 1, 2, and 4 hrs. after treatment with the synergists sesame oil concentrate, "piperonyl cyclohexanone," and n-isobutylundecylenamide. The 1-hr. delayed treatment appeared to be especially effective with the 2 former compounds. In a supplementary test in which pyrethrum was applied 1, 7, 24, 48, and 72 hrs. after the sesame oil concentrate, the 10-min. knock-down was as satisfactory at 24 hrs. as it was at 1 hr. The synergist-pyrethrum mixture was as effective as the separate treatments except in the case of "piperonyl cyclohexanone," which proved better in the separate treatments. When the pyrethrum was applied as the initial treatment followed by the synergists at 1, 2, and 4 hrs., the knock-down was nearly zero in all cases.