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

<i>Phthorimaea absoluta</i> releases (<i>E</i>3,<i>Z</i>8,<i>Z</i>11)-tetradeca-3,8,11-trienyl acetate (<i>E</i>3,<i>Z</i>8,<i>Z</i>11-14:OAc) and (<i>E</i>3,<i>Z</i>8)-tetradeca-3,8-dienyl acetate (<i>E</i>3,<i>Z</i>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 <i>P. absoluta</i>. First, we identified five putative PRs by transcriptome sequencing, i.e., <i>PabsOR4</i>, <i>PabsOR8</i>, <i>PabsOR12a</i>, <i>PabsOR14</i>, and <i>PabsOR17</i>. These receptors are predominantly expressed in the male antennae. Next, we expressed them in <i>Drosophila</i> OR67 neurons and investigated their responses. PabsOR14 and PabsOR8 selectively respond to the main component, <i>E</i>3,<i>Z</i>8,<i>Z</i>11-14:OAc with different sensitivities, while PabsOR17 is tuned to the minor component, <i>E</i>3,<i>Z</i>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, (<i>Z</i>)-7-dodecenyl acetate (<i>Z</i>7-12:OAc). Lastly, we demonstrated that <i>Z</i>7-12:OAc can replace <i>E</i>3,<i>Z</i>8-14:OAc to attract virgin males. Our findings elucidate the peripheral coding of the sex pheromone in <i>P. absoluta</i>, providing a new perspective for controlling it.