  As in many species, gustatory pheromones regulate the mating behavior of Drosophila. Recently, several ppk genes, encoding ion channel subunits of the DEG/ENaC family, have been implicated in this process, leading to the identification of gustatory neurons that detect specific pheromones. In a subset of taste hairs on the legs of Drosophila, there are two ppk00-expressing, pheromone-sensing neurons with complementary response profiles; one neuron detects female pheromones that stimulate male courtship, the other detects male pheromones that inhibit male-male courtship. In contrast to ppk00, ppk00, is only expressed in a single gustatory neuron per taste hair, and males with impaired ppk00 function court females at reduced rates but do not display abnormal courtship of other males. These findings raised the possibility that ppk00 expression defines a subset of pheromone-sensing neurons. Here we show that ppk00 is expressed and functions in neurons that detect female-specific pheromones and mediates their stimulatory effect on male courtship. Furthermore, the role of ppk00 and ppk00-expressing neurons is not restricted to responses to female-specific pheromones. ppk00 is also required in the same subset of neurons for stimulation of male courtship by young males, males of the Tai0 strain, and by synthetic 0-pentacosene (0-P), a hydrocarbon normally found at low levels in both males and females. Finally, we unexpectedly find that, in females, ppk00 and ppk00-expressing cells regulate receptivity to mating. In the absence of the third antennal segment, which has both olfactory and auditory functions, mutations in ppk00 or silencing of ppk00-expressing neurons block female receptivity to males. Together these results indicate that ppk00 identifies a functionally specialized subset of pheromone-sensing neurons. While ppk00 neurons are required for the responses to multiple pheromones, in both males and females these neurons are specifically involved in stimulating  As in many species, gustatory pheromones regulate the mating behavior of Drosophila. Recently, several ppk genes, encoding ion channel subunits of the DEG/ENaC family, have been implicated in this process, leading to the identification of gustatory neurons that detect specific pheromones. In a subset of taste hairs on the legs of Drosophila, there are two ppk00-expressing, pheromone-sensing neurons with complementary response profiles; one neuron detects female pheromones that stimulate male courtship, the other detects male pheromones that inhibit male-male courtship. In contrast to ppk00, ppk00, is only expressed in a single gustatory neuron per taste hair, and males with impaired ppk00 function court females at reduced rates but do not display abnormal courtship of other males. These findings raised the possibility that ppk00 expression defines a subset of pheromone-sensing neurons. Here we show that ppk00 is expressed and functions in neurons that detect female-specific pheromones and mediates their stimulatory effect on male courtship. Furthermore, the role of ppk00 and ppk00-expressing neurons is not restricted to responses to female-specific pheromones. ppk00 is also required in the same subset of neurons for stimulation of male courtship by young males, males of the Tai0 strain, and by synthetic 0-pentacosene (0-P), a hydrocarbon normally found at low levels in both males and females. Finally, we unexpectedly find that, in females, ppk00 and ppk00-expressing cells regulate receptivity to mating. In the absence of the third antennal segment, which has both olfactory and auditory functions, mutations in ppk00 or silencing of ppk00-expressing neurons block female receptivity to males. Together these results indicate that ppk00 identifies a functionally specialized subset of pheromone-sensing neurons. While ppk00 neurons are required for the responses to multiple pheromones, in both males and females these neurons are specifically involved in stimulating  