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.

Fire ants shock homeowners

An incident last month in Carrollton, TX highlights the need for consistent fire ant control, the sort of service residential pest control companies excel at. In this case fire ants invaded a transformer box in a residential area, resulting in a power surge that cost nine surrounding households thousands of dollars. The resulting surge damaged sensitive electronics including garage door openers, dishwashers and microwaves.

Fire ants pose problems for electrical equipment throughout their range in the southeastern US, and now in parts of California. Pad mounted transformers, like the one damaged last month in Carrollton, air conditioning units, traffic controllers, swimming pool pumps and just about any outdoor electrical equipment is at risk.

Why electrical equipment? There are several theories and some data to explain the fire ant's apparent affinity for electrical wiring, switches and equipment. Research done at Texas A&M University in the 1980s showed that fire ants are attracted to the electrical fields that surround wires and especially relay switches. In addition there is some evidence that ants that receive shocks at a relay switch point, for example, release an alarm pheromone that draws other ants into the site. Finally, ground mounted electrical equipment is often warmer than the surrounding soil and probably attracts fire ants to build mounds nearby, especially during winter months. All these things add up to big problems with fire ants (Note: other ant species can cause the same types of problems, presumably for the same reasons).

Why don't utility companies just treat these boxes? Many utility companies do treat any transformers where they find evidence of fire ant activity, but the treatments have a limited life, and the numbers of transformers out there (in the millions) are overwhelming. It is just not economical or practical to treat all electric utility equipment, not to mention every air conditioning unit out there.

Guess where that leaves you as PMPs? It leaves you at the forefront of protecting your customers' homes and property. After working with utility companies and the military for several years on these problems I concluded that the best protection for sensitive equipment is ongoing, thorough fire ant control on the properties where such equipment is located. No other approach works as well.

Residential monthly or quarterly service is an ideal time to provide landscape fire ant control. It's easy for the average homeowner to overlook a regular fire ant inspection and treatment, but building this service into regular pest control treatment provides superior protection against these problems. If your routine pest control service does not provide an option for regular fire ant control you might be missing out on a valuable and useful service for your customers.

It's important to note that landscape fire ant control does not mean treating fire ant mounds piecemeal, only as they are observed. This is the most common, but not the most effective, approach. Landscape fire ant control means using broadcast baits (MaxForce^®, Amdro^®, Extinguish^® and similar products) or granular treatments (usually products containing fipronil or bifenthrin) over the entire area to be protected. Only this approach will control the small colonies that are frequently missed by individual mound treatmens. Only landscape fire ant control will free you and your customers from continually being on the defensive against these ants. For more information about using baits as part of a landscape fire ant control program, see Extension publication B-6099, Broadcast Baits for Fire Ant Control.