ABSTRACT
In many moth species, the sex pheromone consists of a mixture of two or more compounds or of positional or geometric isomers of the same compound. The individual compounds, being similar in structure, have similar vapor pressures and the female moth would be expected to emit the total pheromone at precise ratios of components throughout a range of temperatures. The marginal definition of the pheromone plume, which is sharper at higher pheromone concentrations, has also been postulated to influence male flight. One direct effect of variation in wind speed on the behavior of moths is the apparently adaptive decrease in the period of pheromone emission by female moths with increase in winds. Development of accurate, specific, and highly sensitive analytical methods for pheromones and related compounds in air is a prerequisite to successful direct measurement of the dispersion of the vapors in the atmosphere.
