The effects of predation risk on female silk deposition and male response to predator-cued conspecifics in the wolf spider, Pardosa milvina (Araneae: Lycosidae)

Abstract

Female Pardosa milvina (Hentz 1844) wolf spiders advertise sexual receptivity toward males via silk draglines, and male P. milvina exhibit conspicuous courtship behavior when encountering silk from females. Previous studies suggest that female P. milvina may benefit by limiting silk advertisements and excreta deposition when encountering silk from the predator, H. helluo, and male P. milvina may exhibit corresponding reductions in courtship when encountering silk from conspecific females previously exposed to H. helluo silk. We tested these predictions by comparing the amount of silk and excreta deposited by unmated female P. milvina exposed or not exposed to predator cues (silk and excreta) from H. helluo. We also measured and compared male P. milvina courtship latency and intensity in the presence of silk from females previously exposed or not exposed to predator silk from H. helluo. Contrary to predictions, we found a significant increase in excreta, dragline, and attachment disk deposition after females were exposed to H. helluo cues. Male P. milvina courtship latency did not vary among treatments despite increases in female silk deposition, but males significantly decreased courtship intensity when exposed to silk from females under predation risk. Vertical climbing to escape the predator cues may cause an increase in female silk deposition.