Chemoreceptors distribution and relative importance of male forelegs and palps in intersexual chemical communication of the wolf spider Pardosa astrigera

The chemoreceptors distributed on forelegs and palps of male wolf spiders are known to be involved in intersexual chemical communication, yet their distribution pattern and relative importance are supposed. This study employed scanning electron microscopy (SEM) to determine chemoreceptor morphology and distribution pattern on male forelegs and palps of the wolf spider Pardosa astrigera. We also performed behavioral assays to determine their relative importance in intersexual chemical communication. Although the fine structure of the chemoreceptors distributed on male forelegs and palps did not differ greatly, the chemoreceptors were more widely distributed on palps relative to forelegs. When the chemoreceptors of palps were chemically ablated with zinc sulfate, male courtship latency was significantly prolonged and courtship intensity significantly suppressed as compared to those of the forelegs-ablated and/or control ones. Therefore, we conclude that the contact chemoreceptors are mostly distributed on male palps, thereby males locating their mates through dragline-mediated female pheromone.