Turfgrass and Insects
Ants produce unsightly earthen mounds that can thin the surrounding turf. Excavating soil can damage roots. Most ant species occurring in turfgrass seldom cause serious damage.
Missouri is home to about 100 species of ants. About one-fourth of these may enter homes in search for food, but only about a dozen species are common house pests.
The activities of most ants do not adversely affect humans. Some prey upon other insect pests and are considered beneficial. Many ants are capable of stinging and some, such as the fire ants in the southern United States, are severe threats to humans.
Some ants damage desirable plants by stealing seeds, chewing on the plant and nurturing insects that injure the plant — such as aphids. The presence of ant mounds may be undesirable in lawns, parks and golf courses.
The most common conflict with man, however, is when ants invade the home in search of food. They may contaminate food and become pests simply by their presence.
Ants build nests in the soil, in the lawn, under concrete slabs, stones or boards, and adjacent to foundation walls, in the walls of a house, or in decaying wood or other cavities. The pharaoh ant, carpenter ants and the odorous house ant are exceptions that readily nest indoors as well as outside.
Ants are social insects and live in colonies with three distinct adult castes: queens, males and workers. The immature stages consist of eggs, larvae and pupae. Unlike other social insects, an ant colony may pick up its young and move if disturbed.
The key to controlling most ant species is to locate their nest and apply an appropriate insecticide. Ants usually follow a path, marked by pheromones, from their nest to the food source and back. By observing and following this path, you may discover the nest.
If the nest is not found, spray windowsills, door thresholds and other openings, baseboards behind and under cabinets and appliances, and other surfaces.
Since only the worker ants are killed this way, retreatment may be necessary. One must continue to kill workers until none are left. Individuals back in the nest starve when there are no workers to feed them.
IPM1020, new June 2003