Biology

Red Imported Fire Ant head. (Photo/United States Department of Agriculture)

Life Cycle of the Red Imported Fire Ant
The general biology of the Red Imported Fire Ant has been determined; however, there are numerous aspects of its biology that are not fully understood. The average colony contains 100,000 to 500,000 workers and up to several hundred winged ants and queens. Queen ants can live seven years or more, while worker ants generally live about five weeks, although they can survive much longer.

The Queen

Red Imported Fire Ant queen (circled).

The queen lives for up to six years; her sole purpose in life is the production of eggs. A fully mature queen can produce 1,000 eggs per day. The Red Imported Fire Ant species is different from some ant species in that two distinct 'lines' have emerged. There are colonies in which there is only one queen (monogyne), and others where several queens are present within a colony (polygyne). Researchers have found that in polygyne colonies there is a dominant queen to which a majority of workers are attracted.

Ant Development
Newly-mated queens lay about a dozen eggs. When the eggs hatch seven to ten days later, the larvae are fed by the queen. Larvae develop in six to ten days, and then pupate. Adults emerge from the pupae in nine to fifteen days. Later on, a queen fed by worker ants can lay up to 1,000 eggs per day.

A generalized time line for each stage:

Red Imported Fire Ant life stages. (Photo/Texas A&M)

• From Egg to Larva — 7-10 days
• From Larva to Pupa — 6-10 days: Red Imported Fire Ant larvae shed their skin four times before pupating
• From Pupa to Adult — 9-15 days
• From Egg to Adult can take from 20-45 days, but averages 30 days

The queen depends on worker ants to care for and feed her.

Brood (Pupae, Larvae)
Red Brood, the immature stages of the Red Imported Fire Ant, are not entirely without means of communication or behavior. Researchers have observed that larvae will rock back and forth to draw attention to themselves so that workers will feed them.

Red Imported Fire Ant worker/forager. (Photo/Jack Kelly Clark, University of California)

Workers/Foragers
Workers/Foragers are sterile females whose work within and outside of the colony is dictated by the needs of the queen and the brood. There are major and minor workers — they are differentiated by head size. Workers in a colony have many roles — nurses, mound builders, mound defenders, and foragers.

Mating Red Imported Fire Ants. (Photo/Texas A&M University)

Reproductives
Reproduction begins with mating flights. When environmental conditions are good (generally after a rain or watering), male ants leave the nest and swarm in the air. The female then leaves the nest and flies into this swarm of males. Males and females mate in flight. Within a short period of time, the male dies. The female — now a queen — then begins the process of starting a new colony.

Red Imported Fire Ant. (Photo/University of California Cooperative Extension)