Peripheral Coding of Sex Pheromones in the Tomato Leaf Miner, Phthorimaea absoluta (Meyrick)

Phthorimaea absoluta releases ( E 3, Z 8, Z 11)-tetradeca-3,8,11-trienyl acetate ( E 3, Z 8, Z 11–14:OAc) and ( E 3, Z 8)-tetradeca-3,8-dienyl acetate ( E 3, Z 8–14:OAc) with a ratio of 90:10 as the sex pheromone. However, how this pest uses pheromone receptors (PRs) to detect the two pheromone components is unknown. Here, we functionally characterize the PR repertoire of P. absoluta . First, we identified five putative PRs by transcriptome sequencing, i.e., PabsOR4, PabsOR8, PabsOR12a, PabsOR14, and PabsOR17 . These receptors are predominantly expressed in the male antennae. Next, we expressed them in Drosophila OR67 neurons and investigated their responses. PabsOR14 and PabsOR8 selectively respond to the main component, E 3, Z 8, Z 11–14:OAc with different sensitivities, while PabsOR17 is tuned to the minor component, E 3, Z 8–14:OAc. In addition, PabsOR4 weakly responds to both sex pheromone components. Moreover, PabsOR17 and PabsOR4 potently respond to a non-sex pheromone compound, ( Z )-7-dodecenyl acetate ( Z 7–12:OAc). Lastly, we demonstrated that Z 7–12:OAc can replace E 3, Z 8–14:OAc to attract virgin males. Our findings elucidate the peripheral coding of the sex pheromone in P. absoluta, providing a new perspective for controlling it.