Red Ants in the Roots of a Bush

Infested Plants

• Red ants infest soil and affect the roots of all types of plants and bushes, feeding not only on the insects in the soil but also plant seeds and tree bark. These ants are among the serious landscape pests in the southern regions of the United States. Besides plants, the aggressive ants can also severely sting humans and animals. The sting can be fatal to people with allergies to the ants.

Damage

• The ants damage shrubs and young trees by stripping plant bark. They start to move their nests into the bases of young trees and bushes during winter, often causing plant death as bark is girdled. Pest feeding damages stems and fruit. Red ants protect a number of other pests such as aphids, increasing damage to plants. The ants then pack soil into the damaged plant areas. A number of fruit growers classify red ants as the worst pest in orchards, seconded by spider mites.

Description

• The worker red ants are dark reddish brown and range in size from 1/16 to 1/5-inch long. The tiny eggs cannot be seen with the naked eye. The four main stages of growth are the egg, larva, pupa and adult. The ants multiply rapidly to create large number of mounded nests 8 to 12 inches high with a diameter of about 18 inches. The pests run up anything that disturbs their nests. It is not uncommon for red ants to create large colonies in rotten logs, walls and under sidewalks.

Control

• Ant baits are recommended as a good control strategy, as these are transported to the colony and help to eradicate large populations. Baits are usually corn grits covered with toxic soybean oil. Apply baits in areas where ants are visible and during daytime temperatures of 70 to 90 degrees Fahrenheit. Use at night during very hot weather, as ants will feed on the baits at night. Avoid use of baits in rainy weather. For treating the mounds of colonies, recommended insecticides include granular formulations of pyrethrin, acephate, permethrin, cyfluthrin or deltamethrin, according to the University of California Extension.