Association of prey quality with environmental odors in the foraging behavior of Pardosa milvina

Modulation of predatory behaviors based on prey profitability can improve overall foraging efficiency by allocating energy reserves towards more valuable prey. Should the value of prey vary predictably across the landscape, predators could also benefit from the utilization of environmental cues to inform their foraging decisions. Here, we present data on context-dependent foraging behaviors of the wolf spider Pardosa milvina (Araneae: Lycosidae). Spiders underwent testing during which subjects were alternately provided cricket prey coated with either a favorable (sucrose) or unfavorable (quinine) solution. Each prey type was paired with 1 of 2 environmental odors such that one odor was always predictive of unfavorable prey and the other was always predictive of favorable prey. We found that P. milvina reduced their attacks over time while differing significantly in behavior towards the 2 prey types. The rate of nonresponses towards the unfavorable prey increased significantly over time compared to the favorable prey, suggesting that spiders were avoiding the former. Our findings indicate that P. milvina can differentiate between environmental odor cues associated with prey type. Additionally, we report on a novel prey handling behavior where spiders would repeatedly drag unfavorable prey along the arena floor between bouts of cheliceral grooming. We propose this behavior may have served to remove quinine from the prey.