Green leaf volatile-detecting olfactory receptor neurones display very high sensitivity and specificity in a scarab beetle

In the Japanese scarab beetle, Phyllopertha diversa, olfactory receptor neurones specific for the detection of so-called general green leaf volatiles (GLV) display a high specificity and sensitivity. Three main types of green-leaf-volatile-detecting receptor neurones specific to ((Z)-3-hexenyl acetate, (E)-2-hexenal and (Z)-3-hexenol, respectively, were identified. Each type responded at a very low stimulus concentration to the key stimulus, and required at least a thousand-fold increase in concentration to respond to any of the other GLVs tested. Flower-odour-and pheromone-detecting receptor neurones were also identified. Olfactory sensilla housing plant-odour- or pheromone-detecting receptor neurones displayed clear morphological differences, and were also separated into different antennal regions.