Tapping modulation of the far infrared (17-microm region) emission from the cabbage looper moth pheromone (sex scent).

Many species of insects communicate with each other by tapping (palpating) their antenna or feet against the bodies of other insects. The male cabbage looper moth (Trichoplusia ni) palpates the abdominal pheromone (sex scent) gland of the female. A thin layer (thick monolayer) of the sex attractant [(Z)-7-dodecen- 1-ol acetate] is easily phase-amplitude modulated by tapping a thin coating of the acetate coated on a wax substrate. The modulated emissions which are narrowband and high amplitude (maserlike) ride on the shifting ir carrier wave emitted by the pheromone molecule.