According to Texas A&M University, aphid ants are pear shaped and only reach between .06 to .14 inch in size. They can be almost any color and have pierce-sucking mouth parts. Root aphid ants use their mouth parts to pierce the roots of the plants, sucking and draining the plants of nutrients. Root aphids are difficult to eliminate, and it is best to begin methods to kill them as soon as they are spotted.
Mix one packet of nematodes with a gallon of water. Pour the nematodes in the soil where your root aphids are living. Nematodes are microscopic worms that live in the soil where your root aphid ants are hiding. They are natural predators and will kill the aphids for you. Best of all, nematodes are safe to use around pets and children.
Mix a pyrethrum-based pesticide with an aphicide, based on the instructions on the product label. The Texas Agricultural Extension Service suggests using these two ingredients together to attack an aphid infestation. Do this if the nematodes are not getting rid of the root aphids quickly enough.
Spray the pesticide on the lower part of the infected plants and on the top of the soil.
Repeat once each week until the root aphid ants are eradicated.
Spray your plants with insecticidal soap once per week to keep any new root aphid ants from discovering and feasting on your plants.