ts have a potential of even expanding the spread throughout much of the United States.
Current and potential distribution of imported red fire ant. Image courtesy of USDA.
Adult fire ants (Genus Solenopisis) are characterized by the presence of a ten-segmented antennae, two-segmented antennal club and two-segmented waste that joins the thorax to the abdomen which is typically darker than the rest of the body. Species identification is somewhat more difficult due to hybridization between the 2 "native" species as well as between the 2 imported species.
Diagram of diagnostic characteristics of red imported fire ant.
A mature colony of fire ants typically consists of 4 main stages: egg, larva, pupa, and adults. Since these are true social insect there is a caste system with different shaped and sized adults that carry out different function within the colony. These adult forms include the polymorphic workers, winged males, winged females and one or more reproductive queens. The egg, larval, and pupal stages (Figure 3) occur within the underground nest and are only seen when nests are disturbed or when they are being carried to a different location by workers (Figure 4). The eggs are small but can be seen with the unaided eye. They hatch into the grub-like legless larvae that are fed by the workers. Ant larvae in general are legless, carrot shaped with a well-developed unpigmented head capsule and are typically hooked at the head end. The larvae will grow and molt (shed their exoskeleton) 3 times prior to molting into the pupae, which are similar in appearance to the adults except that their legs and antennae are held tightly against the body. As with the larvae the pupae lack pigmentation, especially in the early instars. As they mature they begin to turn darker. As discussed in honeybees, the function of the polymorphic workers is determined primarily by age (and to a much lesser degree by size). Younger workers typically care for and feed the brood while middle-aged workers maintain and protect the colony. The old