The mainstream theory of insect olfaction is largely analyzed in terms of time and in light of the published literature. The unlikelihood that pheromones can stick to the sensilla and then diffuse through the wax layer is discussed. Current research in our lab supports the fact that moth pheromone cannot move easily through wax or across wax. The temperature of wax is a factor in diffusion, and insect olfaction in light of this theory cannot explain how insects smell in colder climates. Also, pheromone cannot diffuse across a sea of lymph, especially attached to a pheromone binding protein, in a sufficiently short period of time in order to satisfy current published estimates. Additionally, the presence of pheromone degrading enzymes on the outer cuticle, and the inability to locate and characterize an insect pheromone receptor on the sensory dendrite, all point to the inadequacy of this theory.