FemalePardosa milvinawolf spiders increase silk advertisements when in the presence of silk from courting males

Abstract

Female wolf spider silk is known to elicit searching and courtship behavior among adult males, however variation in the types of silk females deposit, the context in which it occurs, and the role of male silk in courtship displays and female responses has rarely been examined. We measured male Pardosa milvina (Hentz 1844) silk deposition while performing courtship displays. We then examined whether female silk deposition changes when encountering silk produced from a courting rather than a non-courting male and compared these conditions to female silk deposition in the absence of male silk. We measured the quantity of three different types of silk (draglines, cord silk, and attachment disks) deposited by females across substrates previously occupied by a courting male, a non-courting male, or no male. Females significantly increased attachment disk deposition in the presence of silk from a courting rather than a non-courting male. Females also showed elevated dragline deposition in the presence of male silk but whether or not the male was courting had no effect on dragline deposition. Female cord silk deposition did not vary across treatments. Courting males produced significantly fewer attachment disks than non-courting males while dragline and cord silk deposition did not vary. We conclude that females can discriminate between silk from courting and non-courting males and increase attachment disk deposition in the presence of courting males. The number of male attachment disks deposited may be one mechanism by which females can discriminate between silk produced by courting rather than non-courting males.