Confirm Fire Ants’ Presence, Kill Them
Question: I’ve been hearing a lot about red fire ants. What should I do if I spot them in my yard?
M.V., Yorba Linda
Answer: Common in several southeastern states, red imported fire ants are new to California and have recently been found infesting several residential and commercial areas in Orange, Los Angeles and Riverside counties. These ants are small (one-eighth- to one-fourth-inch long), reddish brown and, unlike our native southern fire ant and harvester ant, can quickly produce many nests and colonize your yard.
There is such concern over the ants because they show aggressive behavior when their nests are disturbed and will quickly climb onto the object or person and begin stinging. A sting will burn and then itch, followed by a blister that can become infected, form a white pimple and take several weeks to disappear.
A small percentage of the population is allergic to these stings. If a person is allergic, he or she should seek emergency treatment immediately.
Treat for fire ants only if you are sure you have mounds or an infestation on your property or in your neighborhood. If you suspect you have the insects, call the Pest Hotline for assistance at (800) 491-1899.
There are three recommended treatment methods for the ants, which will be described briefly here. For further information, consult the new fire-ant brochure being distributed by the California Department of Food and Agriculture, Pest Exclusion Branch. You will find it at most nurseries.
One method involves a two-step procedure that is good for large areas and should be conducted once or twice a year. Distribute a bait insecticide labeled for fire ants over the entire area, then treat individual mounds with an approved chemical drench or boiling water. Individual mounds should be treated no sooner than two or three days after bait has been applied.
A second method selectively controls the ants but requires more labor and monitoring than other methods and is not suggested for heavily infested areas. There are chemical and nonchemical options for treating fire-ant mounds on an individual basis.
A third method involves eliminating all mound building and foraging activity in lawns and grass and provides more rapid and dramatic control than the second method. It may be more expensive and generally requires more contact insecticide.
For eliminating and controlling fire ants, there are a number of chemical and nonchemical options, including baits, dusts, liquids, granules, and low toxicity and nonchemical options such as pyrethrins and boiling water.
Have a problem in your yard? University of California Cooperative Extension (UCCE) Master Gardeners are here to help. These trained and certified horticultural volunteers are dedicated to extending research-based, scientifically accurate information to the public about home horticulture and pest management. They are involved with a variety of outreach programs, including the UCCE Master Garden hotline, which provides answers to specific questions. You can reach the hotline at (714) 708-1646 or send e-mail to ucmastergardeners@yahoo.com. Calls and e-mail are picked up daily and are generally returned within two to three days.
