Leg autotomy in the wolf spider Pardosa milvina (Hentz) (Araneae: Lycosidae): a common phenomonon with few costs. ABSTRACT. A number of animals are able to escape predation by sacrificing a body part. Spiders commonly lose legs in encounters with predators or conspecifics. We investigated the frequency of leg loss and the manner in which it affected locomotion and prey capture activities of the wolf spider, Pardosa milvina. In addition, we determined if Pardosa were easier to subdue by the larger wolf spider predator, Hogna helluo, once they had experienced leg loss. A field census demonstrated that Pardosa tended to autotomize members of all pairs of legs with equal frequency but overall leg loss was high and increased significantly late in the season. Laboratory experiments revealed that leg loss had no effect on locomotory behavior or prey capture, however, injured spiders tended to take smaller prey. The ability of Hogna helluo, to attack and subdue 7 or 8-legged Pardosa was not different although 8-legged Pardosa tended to lose multiple legs whereas 7 - legged Pardosa only lost one. These data suggest that the costs of leg autotomy are marginal for Pardosa females and thus support the "spare leg hypothesis" that has been proposed for other arachnids.