Treating fire ants in electrical equipment

Fire ants and other ants are attracted to the warmth and electrical fields associated with outdoor electrical equipment.  This electrical insulation has been chewed and wires bared by fire ants.

Although I blogged about fire ants and electrical equipment over a year ago, it's a subject that deserves repeated attention, especially during these hottest days of the year.  This is the time of year when damage to electrical equipment, and especially air conditioners, is especially troublesome.  One of the less recognized economic impacts of fire ants is the damage they can do to air conditioners, traffic signal controllers, landscape lighting, well pumps, and pad-mounted transformer boxes.  Such damage costs Texans millions of dollars every year. 

One of the oft-forgotten benefits of having a professional service controlling fire ant is the protection of such sensitive equipment.  By providing fire ant control in lawns and landscapes, PMPs provide an important first line of defense for electrical equipment. And control of ants in the equipment itself is a useful, and sometimes critical, second line of defense.  Fortunately, there effective products for this second approach.

Pad-mounted electrical transformers (box in foreground) are
common in residential areas throughout Texas and the
southern states.

Many years ago I was approached by a north Texas utility company to evaluate different products for keeping fire ants out of electrical transformer boxes, you know those ubiquitous green boxes found throughout residential neighborhoods in Texas.  The utility company rarely services these boxes, but when they do they wanted to be able to treat a box quickly and cheaply with a product that would keep fire ants out for a long time (years). 

Unfortunately, we're still looking for the perfect product or long-term treatment for fire ant control in electrical equipment.  But this doesn't mean that there aren't some helpful products out there.  In my research, we found that granular formulations of bifenthrin, tefluthrin and even chlorpyrifos would keep fire ants out of electrical equipment for a year or more. Depending on the label directions of specific products, you should be able to apply a light layer of these insecticides into the base of many types of electrical equipment to suppress fire ant activity for at least a year.

More recently, Molly Keck, our extension IPM program specialist in San Antonio, looked at an additional, novel treatment to keep fire ants out of transformers. In her study, she evaluated an easy-to-apply permethrin-impregnated plastic tape strip that could be placed around the concrete openings inside these (locked) transformer boxes, and found that they worked well to exclude fire ants for 16 months.  These tests, I can attest, are difficult to set up and conduct; but despite their relatively small sample sizes, these products do work.

Keck and extension entomologist Bart Drees also published a fact sheet on the subject of different methods to exclude fire ants from electrical equipment. In it they mention a variety of different products and list manufacturers of these materials if you want to obtain samples for your own use or testing. 

I encourage you to be aware of the different fire ant control options for protecting electrical equipment.  I suspect that this is a service that few of you are offering right now; but it seems to me that treatment of electrical equipment would be a great way to distinguish yourselves from your competition while saving your customers significant money.  It may also save you a customer. 

If you want to bring out the revolutionary fiery spirit of a Texan, let the air conditioner break down in hundred-degree weather due to fire ants.  And I for one wouldn't want to be in that line of fire.