Colonies of Aphis gossypii (Hemiptera: Aphididae) vary in their attraction to Solenopsis invicta (Hymenoptera: Formicidae)

Ant-aphid mutualisms are prolific in natural and agricultural systems. In this mutualistic relationship, aphids provide ants with nutrient-rich excrement, honeydew, and in turn, ants protect aphids from predators and parasitoids. The cotton aphid, Aphis gossypii, is a widespread pest of agriculturally important crops and feeds on dozens of wild plant species. Our previous research found that cotton aphids and the invasive red imported fire ant, Solenopsis invicta, readily form facultative mutualisms that benefit both aphids and ants. Our observations of this mutualism led us to hypothesize that different colonies of cotton aphids were more or less attractive to foraging fire ant workers. To test this hypothesis, we quantified the attraction of fire ant workers to cotton aphid colonies from locations throughout Texas. We measured the time to recruitment and sum of recruited ants to individual aphid colonies in enemy-free mesocosms in both choice and no-choice preference trials. We found that aphid colonies varied in both the time to ant recruitment and number of ants recruited, with certain colonies exhibiting higher rates of attraction. Our results suggest that aphid colony level variation may influence ant attraction. Future studies will investigate whether honeydew composition varies by colony and whether ant aggression is correlated with attraction.