New research from Susquehanna University biology professor Matthew H. Persons, published in the the November 2014 issue of “Ethology, shows that female wolf spiders increase their dragline silk advertisements to attract uninterested males. “Previous studies have assumed that females passively produce silk and that males exploit these cues to search for and locate the female,” Persons stated. “We were interested to know what kinds of silk females are making, and if they change how much or what kinds when they see males in the area, or if they change how much or what kinds they make based on what the male is doing.”
Persons and his team scoured corn and soybean fields for wolf spiders. “Most of the time you can collect about 50 per hour and you only need to step a couple of feet into the edge of a soybean or corn field to do it,” he said. “For this study, I think it took maybe a couple of afternoons to collect our study subjects.”
According to Persons, females placed in a petri dish were moved to a larger “arena” that contained a male that they could see but not touch. “Some of the males had access to female silk and would court vigorously. Other males didn’t have access to female silk and so didn’t court much. We then measured the kinds of silk and how much females deposited on the ground while watching these males,” he added.
Over time female spiders were mostly interested in attracting male attention when the males were ignoring them. “What we found was that females produced a lot more silk when they watched males that were not courting compared to when they were. This indicates that they are using silk to try to get a male’s attention.”
Persons reported that the females deposited three different kinds of silk: dragline, cord and attachment disks. Each probably corresponds to a different kind of communication. His study shows that sex pheromones or female-produced silk aren’t produced at a constant rate. Instead, this production is dependent entirely on the male’s actions. The female spiders are actively seeking out mates. The silk is not “a passive cue for males,” but rather an “active sexual advertisement or courtship signal that females are sending to males,” Persons concluded. This revelation is changing the way researchers view the mating habits of spiders.