THE EFFECTS OF MOISTURE AND HEAT ON THE EFFICACY OF CHEMICAL CUES USED IN PREDATOR DETECTION BY THE WOLF SPIDER PARDOSA MILVINA (ARANEAE, LYCOSIDAE)

Abstract

Abstract Little is known about how environmental conditions affect the relative efficacy of information present in chemical cues. The wolf spider, Pardosa milvina, responds to silk and excreta from a larger species of wolf spider, Hogna helluo, with effective antipredator behavior. We investigated whether wetting or heating chemotactile cues of Hogna helluo would reduce the amount of antipredator behavior displayed by Pardosa milvina relative to unmanipulated cues. Pardosa milvina showed less antipredator behavior on chemotactile cues that had been wetted then dried but did not respond differently in the presence of cues that had been heated and then cooled. The results suggest that, in the field, morning dew may degrade some of the cues deposited by H. helluo at night and reduce the ability of P. milvina to avoid predation. However, typical periods of daily heating of cues may not affect the efficacy of predator detection by P. milvina.