The ability of ants to associatively learn based on olfactory chemical cues produced by plants.

Abstract

Associatively learning is commonly observed throughout the natural world in many interactions between species and their environment. We know ants utilize environmental cues in their foraging patterns to locate and recruit to food, but little is known about their ability to associatively learn to forage using these cues. Associative learning in ants has been tested in laboratory settings but the experiment has never been replicated in the field. It is also unknown to what extent the ants learn on certain environmental cues including olfactory cues. After allowing ants to forage and recruit to baits associated with scents produced by plants associated with sugar rich resources (either Ligusticum porteri or Helianthella quinquenervis), we found that additional baits with the same scent were significantly more likely to be discovered than those with the other scent (30-40% more likely to be discovered), although there was no significant difference in how quickly the baits were discovered or the number of ants that recruited to the bait. Furthermore, significantly more ants recruited to the baits if the first bait smelled like Ligusticum porteri as opposed to Helianthella quinquenervis (23% more likely). This result indicates that ants detect plant scents when foraging for sugar rich resources and subsequently forage more frequently for resources on those same plant species. This learned association could increase the capability of ants to forage successfully and increase the fitness of ant colonies.