Interval between insecticide treatmentsBased on the assumption that the growth of insect populations follows the logistic law, the author developed an equation for the determination of the time interval between insecticide treatments: t= {lpg [100-Po (1-E) / (1 - E) (100 -Po)]} / log p where t = time interval between treatments expressed in number of generations of the species; Po = maximum percentage of infestation, that must not be surpassed (from 0,00 to 100,00); E = efficiency of the insecticide (from 0,00 to 1,00); p = reproduction potential of the species. The theoretical results are discussed.