Red Imported Fire Ant Infestation Discovered in Orange County

For Immediate Release
Wednesday, November 18, 1998
Release CDFA98-117

Contact: Alfreda Sebasto
Myrlys L. Williams
Oscar Hidalgo
(916) 654-0462

RED IMPORTED FIRE ANT INFESTATION DISCOVERED IN ORANGE COUNTY

CDFA CONDUCTING EXTENSIVE SURVEY IN THE AREA

SACRAMENTO – California Department of Food and Agriculture (CDFA) officials are investigating an infestation of Red Imported Fire Ant (RIFA) that has been found in southern Orange County.

Initial reports of the infestation were provided last week by the Nevada Department of Agriculture, which intercepted infested nursery plants shipped from the Trabuco Canyon area of Orange County.

CDFA officials found two nurseries in Orange County infested with fire ants. Further visual surveys in the residential area surrounding the nursery, primarily along Robinson Ranch Road, revealed an estimated 70 to 100 fire ant mounds. It is the first known discovery of Red Imported Fire Ant in a residential area of California.

CDFA officials are continuing to survey a 10-square-mile area in Trabuco Canyon, Coto de Caza and Rancho Santa Margarita. An eradication strategy will be determined early next month following a meeting of national and international experts on the pest.

In fire ant infestations elsewhere in the United States, treatments include the application of a bait containing an insect growth regulator, fenoxycarb, to each known RIFA colony, or a broadcast application to the infested area. This type of insecticide, when ingested by the queen ant of the colony, effectively sterilizes her, preventing the population from replacing itself.

Red Imported Fire Ant biting and stinging behavior is generally a defensive reaction for protecting food and water resources or their nesting sites. When a mound is disturbed, large numbers of worker ants come to the mound surface to defend the colony. An unsuspecting victim can be rapidly covered with ants.

The ants anchor themselves with their mouthparts and then sting repeatedly. With the sting, venom is injected into the skin. The sting results in a pustule on the skin and an intense burning sensation at the sting site. Although stings are not usually life threatening, a small percentage of the population are hypersensitive to the venom, and may experience complications.

RIFA infest residential yards and gardens, agricultural fields and pastures, electrical control boxes and utility housings, threaten nesting wildlife and newborn animals. During hot and dry weather, the ants invade homes in search of food and moisture. They can pose a threat to sleeping and bed-ridden individuals and pets.

Colony reproduction occurs throughout the year, usually after a rain when temperatures are warm enough. After swarming, the mated female drops to the ground, sheds her wings and begins burrowing into the soil.

The ants are an established pest in 11 southeastern states, including: Texas, Louisiana, Mississippi, Alabama, Florida, Georgia, South Carolina, and adjacent regions in North Carolina, Arkansas, Tennessee and Oklahoma.

It is estimated that in Texas alone, the RIFA causes more than $300 million annually in damage to crops, animals and people. Texas currently spends $2.5 million per year in its efforts to manage the RIFA infestations.

First intercepted at our border stations in 1983, the number of interceptions have increased every year. In fiscal year 1997-98, there were 108 RIFA interceptions at California’s agricultural inspection stations.

If allowed to establish in California, RIFA could eventually spread to all areas of the state, except for the driest deserts and coldest mountain areas.

For additional information on the Red Imported Fire Ant, visit CDFA’s website at: www.cdfa.ca.gov .

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NOTE TO MEDIA: CDFA staff will be available for questions and to direct you to fire ant mounds for photo opportunities tomorrow, November 19^th, from 10:00 a.m. to 10:30 a.m., at the corner of Plano Trabuco Road and Joshua Drive, in Trabuco Canyon.