Abstract
Pyrethrum-oil films were tested in various forms on plaster substrata against the tick, Ornithodorus moubata. The insecticide was most effective if applied :—1. Concentrated rather than dilute.2. In a medium rather than a light petroleum oil.3. As an emulsion in Lanette Wax Solution rather than in oil alone.4. With an irritant (such as 4-chlor-2-methyl-phenol) present in the solution.