Ants and Aphids Have Each Other's Back by Angelica Elliott

 

Photo: Pexels

Late last summer, something strange caught my attention while weeding around a Cosmo plant. I noticed a black blob on the plant's main stem. As I got closer to inspect, I realized it was a thick colony of black aphids (family Aphididae), and from my experience, where there are aphids, there will likely be ants.

It is no surprise to find ants hanging around with the aphids. The ants purposely corral the aphids under leaves and keep them out of the sight of potential predators like lady beetle larvae, lacewings, and more. Aside from offering the aphids protection, the ants also transport aphids from plant to plant. In return, the aphids feed the ants, providing enough food for their colony.

Photo: Angelica Elliott

After sucking the sap from plants, the aphids secrete a sweet honeydew-like substance that ants love to feed on. Any residual honeydew left behind after the ants and aphids have moved on will result in a black, sooty mold and fungus. The plant's appearance may also be affected and potentially carry disease.

The adult female aphids can have offspring without the need to mate. They mature into adults in about 8-10 days, hence why they populate so quickly—the more, the merrier for the ants.

Sources:

https://www.britannica.com/animal/aphid

https://ipm.ucanr.edu/PMG/PESTNOTES/pn7404.html#:~:text=Young%20aphids%20are%20called%20nymphs,of%20foliage%20on%20deciduous%20plants.

https://extension.umd.edu/resource/aphid-parasitoids

https://www.heartspm.com/farming-aphids-herder-ants-a-k-a-farmer-ants.php