 |
 |
 |
| |
 |
 |
 |
 |
 FIELD ANTS
Common Name: Field ant
Scientific Name:Formica species
Introduction. The common name of field ant probably comes from their abundance in outdoor situations. This is the largest genus of ants in America north of Mexico, containing about one-sixth of our entire ant fauna. Some species are commonly called thatching ants because of their habit of constructing a mound or thatch of plant material, often grass. They are found throughout the United States.
 Recognition. Field ant workers measure about 1/4 inch long and may be brown, black, reddish or a combination of these colors. The thorax profile is not evenly rounded on upper side. There is a distinct notch halfway or so along the top surface of the thorax. The waist (pedicel) of the abdomen is 1-segmented (single node). Although no stinger is present, these ants will bite and spray pungent-smelling formic acid onto the persons or animals provoking them.
Similar Ants. Carpenter ants (Camponotus species) have the upper surface of
the thorax evenly rounded as observed from a side (profile) view.
Biology. Because of the size and diversity of this genus, few generalizations can be made. They exhibit such behavior as slave-making and temporary social parasitism of various kinds, and several different methods of nest construction. Colony founding is usually by a single mated female (queen). Colony size varies considerably, for example, colonies of some species have nests of about 20,000-94,000 ants.
Habits. The habits are diverse within this genus. However, most species causing problems around structures are either one of those species called thatching ants or are associated with masonry walls, concrete sidewalks, etc.
Thatching ant species construct their mound of plant materials, often grass but also twigs, leaves, and/or pine needles. Such nests are often located around small trees, shrubs, or rocks. Other Formica typically construct their nest in the cracks of sidewalks, along foundation walls, at the base of trees, etc. Field ants rarely nest in homes but occasionally enter in search of sweets.
Field and thatching ants feed primarily on honeydew from aphids (plant lice), mealy bugs, scale insects, etc. found on trees and shrubs. However, some are also general scavengers-predators and are attracted to meats.
 Cultural Control & Preventative Measures. One should quickly clean up food and beverage spills from floors, porches and decks (including pet food) to discourage foraging by these ants indoors and near residences / buildings. Field ants that occasionally enter buildings can be removed with a vacuum cleaner fitted with a hose attachment.
Trees that are infested with honeydew-producing insects can be made less attractive to foraging ants by periodically spraying the trunks with a 1 or 2% detergent solution in a 2 to 3 foot high band pattern at the base.
Professional Control. A Rottler technician will apply a perimeter treatment with a residual insecticide to discourage structural entrance by field ants. Spot treatments using residual or bait insecticides will be made to obvious mound nests located in the ground.
Locations
Serving the St. Louis Metropolitan area since 1956, including
Arnold, Ballwin, Chesterfield, Crestwood, Creve Coeur, Des Peres,
Fenton, Florissant, Kirkwood, Maryland Heights, Overland, St.
Charles, Webster Groves, Wentzville and surrounding areas.
In Illinois: Belleville, Collinsville, Edwardsville, Columbia,
Madison, Waterloo, O’Fallon, Granite City, Alton, St. Clair, Monroe
and surrounding areas.
Columbia & Jefferson City, MO and surrounding areas. |
 |
 |
 |
 |
|
|
 |
 |
 |
|
|
|
 |
|
|
|
