Multiple web-borne pheromones in a spider Frontinella pyramitela (Araneae: Linyphiidae)

The bowl-and-doily spider, Frontinella pyramitela, is a common inhabitant of low vegetation throughout most of temperate North America. All instars build concave-upward, bowl-shaped, nonviscid webs supported above and below by meshworks of silk. Previous studies of this species have revealed that chemical(s) on the silk of adult females elicit both courtship behaviour and positive geotaxis from adult males that contact the silk. This study demonstrates (1) that two different contact pheromones are responsible for the dual action of the silk of adult females and (2) that the webs of different age and sex classes of bowl-and-doily spiders (including the webs of adult males) contain functionally different mixtures of the two pheromones.