The effects of prenatal predator cue exposure on offspring substrate preferences in the wolf spider Tigrosahelluo

Abstract

Prey may gain fitness benefits from recognizing predators at an early age. Predator cues perceived by gravid prey have the potential to prime offspring to alter their behaviour in the presence of predation threats after birth. Wolf spiders (Araneae: Lycosidae) provide an opportunity to explore this phenomenon since females carry their eggsacs prior to eclosion and, after emergence, carry spiderlings for days as they disperse. During maternal care, mothers may prenatally expose offspring to predator odour cues and potentially influence their posteclosion dispersal when in the presence of these cues. Spiderlings of the wolf spider Tigrosa helluo are eaten by adults of the wolf spider Pardosa milvina . We measured differences in substrate preferences of spiderlings produced from egg-carrying T. helluo females that had or had not been exposed to cues of adult P. milvina . Over a 15-day period we counted the number of offspring climbing on substrates previously walked on by P. milvina , crickets or blank control substrates. For the first 10 out of 15 days, spiderlings of predator-exposed mothers climbed on Pardosa substrates significantly more compared to control mothers. We found no significant spiderling preference in time spent on cricket-cued or control substrates across treatments and no difference in chemical cue substrate preference of the mothers while spiderlings dispersed. Among wolf spiders, vertical climbing and contact with predator-cued substrates can induce adaptive tonic immobility (freeze response) that has been associated with increased survival in the presence of live predatory lycosids. Spider predator cues may prime spiderling antipredator behaviour either directly through prenatal exposure in the eggsac or indirectly by modifying the mother's behaviour prior to eclosion, but we found no evidence of mother substrate preference influencing spiderling distribution during dispersal. • Embryonic wolf spiders are primed to learn predator cues while in the eggsac. • Spiderling dispersal differed based on predator cue exposure during eggsac care. • Shifted antipredator responses persisted for at least 10 days postemergence.