Threats from red imported fire ants

        The polyphagous RIFA may have negative impacts on many organisms in the local ecology. It also negatively affects soil microorganisms. Earthworms are killed or attacked by foragers around RIFA-infested areas. RIFAs also gather seeds, fruits, buds, and roots of crops. RIFAs cause economic losses by affecting the growth of plants and production of crops.

i. Impacts on the ecology

          RIFAs prey on several invertebrates and decrease their biomass, population, and diversity in the local ecology. Thus, many local ant species might die out due to an invasion by RIFAs. RIFAs are more aggressive than other species when searching for food sources.

It was reported that fire ants will attack several terrestrial vertebrates such as bird eggs and nestlings, lizard eggs and younger individuals, small mammals, rodents, and others.

Therefore, RIFAs can affect local natural ecosystems. They collect and feed on seeds that can change the ratio and distribution of seeds of various species.

ii. Destruction of public property

RIFAs affect public property and electric equipment such as electric boxes, poles of electric transformers, switchboard boxes, and traffic lights and also cause some equipment to fail. It is reported that in Texas , the RIFA causes damage to public property in excess of US$1 billion every year. 

iii. Impacts on public health

        The fire ant’s sting creates painful burns because of its characteristics, for which it is named.

A white pustule forms from a RIFA sting that is similar to a burn. A mature nest contains about 200,000~500,000 workers. If a nest is disturbed, workers begin to emerge from the nest and attack the invader. The RIFA uses its mandibles to bite; fire ants inject venom from a venom sac into its prey and may bite 7 or 8 times. The RIFA venom contains a high quantity of formic acid and many types of toxalbumin that can cause serious burning effects. Those effects can continue for more than 1 h. A white pustule forms on the part of the body that was stung after 4 hours.

A secondary bacterial infection in the white pustule area may occur and that might cause cellulitis.

           Some people are sensitive to the toxalbumin of RIFA’s venom, and some people have

died from allergic shock. General symptoms of taxalbumin poisoning are a dry and red face, general inflammation, spots, swelling of the face, eyes, and throat, chest pain, cessation of breathing, speaking difficulties, paralysis, and heart problems It is reported that in South Carolina , US in 1988, about 33,000 persons sought medical advice due to RIFA bites, 15% of whom were affected by partial allergic reactions and 2% of whom were affected by serious allergic reactions leading to allergic shock. An average of 2 deaths a year are reported due to RIFA bites in the US .

iv. Economic impacts

        In Texas , fire ants cause economic losses of about US$300 million annually. These losses are due to damage to livestock, crops, and public health as well as ecological impacts. In South America , economic losses due to RIFAs are about US$5 billion with about US$750 million in the agricultural sector.