Do Ants Use Aphids?
WouterWhether ants use aphids is a question that has been debated. Ants are known to carry aphids to their preferred food sources, and some ants are known to tranquilise aphid colonies. The relationship between ants and aphids is not well understood, and the mechanisms behind mutualistic interactions are not well understood.
Researchers investigated aphid diversity between ant nest mounds. They found that aphids spatially separated in ant mounds were often multiple species or clones. This diversity deviated from a random distribution.
In addition to investigating the diversity of aphid species, the researchers investigated the frequency of ants tending to aphids. They found that ants picked up living aphids, sporulating aphid cadavers, and non-diseased aphid cadavers. Ants also tracked tending events. Ants also removed aphid cadavers that had been infected with a non-epizootic fungal entomopathogen.
Ants used chemicals on their feet to calm and subdue colonies of aphids. This was a highly evolved behavior. Ants also carried the aphids to new food sources. During the winter, ants also carried aphid eggs to temporary host plants. These findings suggest that ants have evolved multiple defences against epidemic disease.
These findings suggest that ants may not actually use aphids, but rather they tend to aphids. They may carry aphids to their preferred plant, eat honeydew, and protect aphids from insect enemies. Ants may also use chemicals to subdue colonies of aphids. Whether ants use aphids or not, the findings are a reminder that ants are an important part of our garden ecology.
