Ant behavioral responses to high aphid predators in high and low traffic environments.

Abstract

Mutualistic relationships are a critical component of behavioral and community ecology because these relationships help organisms survive, grow, and reproduce. Specifically, in mutualistic relationships, one organism may provide protection from predation for another individual. We sought to determine if the mutualism between ants and aphids is affected by human activities, particularly disturbance due to human foot and vehicular traffic. To determine if ant behavior in response to aphid predators varied between high and low traffic areas, ant species composition , and variation in average temperature, we measured protective and non-protective ant response behaviors on milkweed plants at the University of Michigan's Biological Station. We also collected biological samples of ant species found on each milkweed plant we sampled and took average temperature readings before and after our sampling period. We found that tending behaviors were significantly greater in high traffic areas and ignoring behaviors were significantly higher in high traffic areas when aphid predators were not present. Additionally, ant species composition and average temperature did not have a significant effect on ant behavior. Our results show that ants exhibit protective behaviors in response to aphid predators in general, suggesting that ants benefit from the resources they receive from aphids and mutualistic relationships between these two organisms are strong in this geographical region. Our findings are relevant to ecological scientists interested in researching mutualistic relationships and human influences on the environment, as well as those involved in agriculture and land development industries investigating insects that provide important ecosystem services and pests that cause large amounts of crop losses each year.