Imported Fire Ants

Pestgon FactSheet

IMPORTED FIRE ANT: (Solenopsis invicta or Solenopsis wagneri)

Description:
Fire ants are small (less than a quarter of an inch long), and look very much like ordinary house or garden ants. This species can easily be confused with common native ants. Imported Fire Ants are coppery-brown to black and live in colonies that consist of visible dirt mounds that can become as large as a washtub, with long underground tunnels. The nest mounds have no obvious entry or exit holes on top of them.

Their dome-shaped nest mounds can be found next to, or underneath objects on the ground, such as boards, rocks, pavers, bricks etc. Pestgon, Inc. has noted that mounds will not always be evident, and are usually found in open areas such as lawns, landscape, fields and along pathways. These ants also establish colonies under sidewalks and roadways.

Biology:
Since the early 1920s these aggressive and destructive creatures have slowly migrated throughout most of the southern United States. They are now present in southern California and are developing as a serious threat to both people and property. All wingless ants are workers, sterile females. The winged forms, or reproductives, live in the mound nest and swarm twice a year, usually in the afternoon, soon after a rain. Swarming is most common in spring and fall. Fire ants can be destinguished by their aggressive behaviour, particularly near the nest. They are venomous and highly mobile. Only a small percentage of persons are sensitive to the venom and experience serious redness and swelling or allergic reactions.

Economic Impact:
Imported fire ants cause significant damage to plants in irrigated landscapes. They are especially destructive to turf grass areas and their unsightly dirt mounds cause damage to mowing equipment. Pestgon, Inc. has found that these ants can collect in large numbers in electrical switching equipping, causing expensive shut-downs. Fire ants also nest within urban structures such as the walls of commercial buildings, offices and homes. Building invasions can threaten the occupants, especially children and the elderly. Such invasions are especially prevalent during periods of heavy precipitation and flooding.

One of the greatest economic impacts and dangers posed by the Imported Fire Ant results from short circuits and fires in electrical systems when the ants move into circuit breakers, relays, motors, and other electrical devices. Fire ants are attracted by electrical currents and have caused considerable damage to heat pumps, air conditioners, telephone junction boxes, transformers, switches, etc. Why certain ants are drawn to electrical currents is still something of a mystery.

Management Methods:
Pestgon, Inc. employs a combination of Integrated Pest Management techniques to prevent and eradicate this serious pest. Pestgon, Inc. recommends a monthly pest management service and thorough inspections in order to prevent the establishment of Imported Fire Ant colonies.

Additional Links:

http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn7487.html