RED IMPORTED FIRE ANT:Solenopsis invicta, Formicidae

ADULT: Reddish- to dark-brown ants with obvious swollen double node bridging the constriction between the thorax and abdomen. Adults are quick to bite exposed skin or clothing (particularly when the colony is disturbed) and then use their stingers at the end of the abdomen to inject venom. Most other ants encountered in Florida corn fields will not act this way.

EGG, LARVA, PUPA: The immature stages are passed within the colony in the soil.  Pale, legless larvae are cared for by adults.  All appendages are visible on pale pupae.  Raised mounds are noticeable in undisturbed soil, but are usually not obvious in cultivated soil.

DAMAGE: Fire ants are only occasional pests of Florida corn.  They attack young plants from beneath or at soil level, and tunnel up into the plant to eat the soft moist crown and bud tissue. Damage is most likely in fields recently sanitized by cultural and chemical control strategies for weeds and arthropods. Ants in colonies surviving these activities have little left to eat and are known to attack and kill a variety of vegetable and field crops. Drought conditions can also bring on attack of the plants when the ants have become severely moisture stressed.

CONTROL: Pesticides are available for banded applications at plant and post-emergence.  At-plant applications may be necessary when planting into fields that may have become heavily colonized by fire ants through an extended period of fallowing. Formulations, rates, and pre-harvest intervals of insecticides for fire ant control are listed below for sweet corn (Table 1) and field corn (Table 2).