Sex and the Sierra Dome Spider
Paul J. Watson’s work originally appeared in 1986 in the journal Science:
Watson, P. J. 1986. “Transmission of a female sex pheromone thwarted by males in the spider Linyphia litigiosa (Linyphiidae),” Science 233:219-221.
The pheromone of a spider that is closely related to the Sierra Dome spider and shows similar behavior has been chemically identified by a research Group in Denmark. The compounds (R)-3-hydroxybutyric acid and (R)-3-[(R)-3-hydroxybutyryloxy]-butyric acid are the first pheromones identified from a spider. Both compounds trigger web reduction behavior by Linyphia triangularis (Clerck) males. The research was published in 1993, also in Science:
S. Schulz, S. Toft, “Identification of a Sex Pheromone from a Spider,” Science 1993, 260, 1635-1637
Watson adds “This pheromone may be the only example of a female organism advertising to the opposite sex the availability of a fertile mating. Most female pheromonal or other sexual displays advertise quality, not availability or fertility. The reason that females typically do not evolve fertility displays is because they generally don’t have to, that is, there is no selection pressure to do so. This is because there is such strong selection on males of the species to pick up on inadvertent cues that tell them the location and fertility of females. Even in Sierra Dome spiders, the fertility display is seldom seen, and probably is most often used by females that are living on the extreme fringes of a population, where males are very scarce, and/or by females that mature very late in the breeding season when most males are already dead.”