How to treat Red Imported Fire Ants
What You Can Do
Because RIFA represents such a serious threat, homeowners may be tempted to treat on their own. Unlike other vector issues, the Orange County Mosquito and Vector Control District (District) discourages the public from doing anything but calling in a report. The District Inspectors typically use an insect growth regulator (IGR), a product that inhibits development of the immature ants. This results in a decrease in replacement ants and as the workers die off, so does the colony. The active ingredients found in most pesticides that are currently available will kill ants, but not colonies. In fact, as the queen notices the effects of the poison on her workers, she will often move the entire colony. This is complicated by the fact that a single colony may have several queens, each one headed in a different direction with an entourage of workers.
Studies have shown that homeowners are far more likely to apply excess pesticides, sometimes many times the recommended amount. This results in polluted runoff and the possible removal of an otherwise effective material from the market.
Orange County residents are encouraged to be vigilant in their own yards as well as any time they are visiting a park, golf course or any place that has a large turf area. Red Imported Fire Ant colonies are distinct but southern California colonies rarely build the large mounds typical of RIFA in other parts of the country. Almost all of the mounds in Orange County are found in irrigated areas, most often turf which gets mowed every week. Look for a patch of fine granular soil where it doesn't belong; for example, in the middle of a lawn. It is possible that if a colony has settled into an irrigated planter or other landscaped area, a mound will develop, usually at the base of a shrub. Another common location is adjacent to a hardscape feature like a large rock or a concrete walkway. These large, dense objects store heat during the day and release it slowly during the night.
For the District's specific guidelines on how to avoid or reduce mosquitoes, rats, red imported fire ants, and flies please refer to recommendations in the document below.