The cutting edge of insect olfaction

Odor discrimination by insects can be exploited by entomologists to make species-specific pheromone traps and mating disruptants or to manipulate insects via host odors. Recent neuroanatomical studies have revealed how odor blends are represented by antennal neurons and their associated target glomeruli in the first layers of the brain as the relative abundance of each individual component in the blend. Further processing by neurons deeper in the brain decodes these lines of component-specific information and integrates them to produce enhanced signals that represent the blend quality. This article describes techniques that have aided in tracing and mapping olfactory pathways, thereby improving our ability to design new strategies for shortcircuiting odor-mediated insect behavior.