How do male moths locate pheromone sources?

The ability of male moths to locate a pheromone-emitting female over distances of tens and perhaps many hundreds of meters has long fascinated entomologists. Fabre's account of dozens of male Great Peacock Moths descending on his study in search of a single calling female suggested that males might have been summoned from quite some distances away. The navigational principles that moths and other flying insects use to navigate toward an upwind source of female pheromone is simply pheromone-induced optomotor anemotaxis. It is not, as some occasionally still believe, following an odor gradient. But a full understanding of the navigational mechanisms used is contingent on how these odors are distributed in space and how moths respond to odor contact and loss. Joe Elkinton has played a pivotal role in field experiments with Lymantria dispar, the spongy moth, to establish plume structure, how these moths navigate along a plume, the distances travelled, and in the use of pheromone-baited traps for surveillance.