Introduction


Biology

Classification 

Invasion history and dispersal routes

Threats

Detection and monitoring 

Control

Bite and sting treatment

 Biology

     As with many insects, the life cycle of the red imported fire ant (RIFA)is also divided into 4 stages of the egg, nymph, pupa, and adult. The RIFA is a eusocial insect. A single RIFA colony is composed with 3 castes: thequeen, and male and laborer ants. Eachcaste has its own specialized job.  

i.   Queen: The queen is the most important member of a RIFA colony. A queen needs about 180 days to develop from egg to adult. A queen reproduces and maintains the progeny of the colony. A queen can live for 6~7 years and produces several hundred to several thousand eggs each day. In addition,about 4500 new virgin queens are produced each year by a mature mound.  

ii Males: Male RIFAs need about 180 days to develop from egg to adult. They are responsible for mating with queens. Males die immediately after mating with a queen.

iii.Laborers: Workers and soldiers are the laborer ants. Smaller and larger workers respectively need about 20~45 and 30~60 days to develop from egg to adult. The major tasks performed by laborer ants are taking care of the queen, foraging, and building and protecting the nest. All laborer ants are sterile females. Laborer ants only live for 1~6 months.

Fire ants have no specific period for mating. Reproductive individualscan be produced from mature nests throughout the year. Generally, queens and males fly about 90~300 m above the ground and mate in the air. A mated queen will then fly about 3~5 km away to build a new nest. A mature nest is a mound 10~30 cm high, 30-50 cm deep, and 30~50 cm in diameter. A newmound can be observed 4~9 months after colony establishment.

RIFAs also build foraging tunnels that are 10~100 m long. RIFA colonies are divided into two types
:
i? Monogyne:
Monogyne colonies contain only 1 queen. Workers in a monogyne colony show highly defensive
reactions to neighboring colonies. About 50,000~240,000 ants can be found in a mature monogyne colony. They can build 200~300 mounds/ha.

ii? Polygyne: Polygyne colonies contain more than 1 queen. Workers in a polygene colony show almost no
defensive reactions to other colonies. In a polygyne colony, about 100,000~500,000 ants can be found.
They can build more than 1000 mounds/ha