Imported Fire Ants in Tennessee

Determining Losses

In a recent survey, ranchers said that fire ant problems are widespread and costly, but vary tremendously from ranch to ranch, even within the same locality. As a result, no one management plan can be used in all situations. Losses must be determined for each individual operation and treatment plans tailored to minimize those losses at an acceptable cost.

Ranchers can make two common mistakes when estimating fire ant losses and deciding on treatments. First, they may not include every loss caused by fire ants that takes money out of their pockets. Dead and injured calves and infested hay bales are obvious losses. However, a shorted-out air conditioner or the cost of treating mounds around the children's swing set also should be included, even though they are not directly related to the business part of the ranch. Survey results show, in fact, that electrical damage and pesticide expenditures are the two most common types of losses.

The second mistake involves treatment options. Fire ant "eradication" is not technically or economically feasible. Still, when many ranchers think of fire ant treatments they think of treating large expanses of land to try to kill all ants. At a minimum of about $15 per acre per year, treating large areas is not usually economical, although some methods can cut large-area treatment costs by up to half. What many ranchers fail to realize is that most fire ant problems occur on fairly small areas that can be treated rather easily and at a modest cost.

Some Points to Remember When Estimating Cost:

Worksheets 1and 2 can help you categorize and tabulate losses. They come in two forms, excel and web formats. Excel form can be downloaded and values entered into the correct columns and values will be calculated automatically. The web form can be printed out for those that do not have Excel.The first is for cattle production (Excel, Web), the second for hay production (Excel, Web). Once you have an accurate estimate of losses you can choose which treatment options are best for you.

Management Strategies

---

Poultry Houses, Livestock Barns, and Feedlots

Imported fire ants on poultry farms can attack chickens and forage on broken eggs. Fire ant stings cause blemishes that can reduce the quality of poultry. Similar problems occur in animal feeding stations, barns and feedlots.

 

Treatment Options:

Program 1:Poultry Houses and Egg Farms

Program 2: Broiler Houses and Turkey Operations

Program 3: Livestock Barns and Feedlots

---

Field Crops and Commercial Vegetables

Red imported fire ants are considered beneficial insects in cotton and sugarcane production, and control is not recommended. In cotton fields, fire ants are effective predators of boll weevils. Fire ants can be sampled using the beat bucket method, whereby the terminals of cotton plants are beaten into a plastic bucket to dislodge insects. Insecticides usually are not needed for boll weevil control when an average of four or more fire ants is collected per ten terminal samples in mid to late season cotton. In Louisiana sugarcane fields fire ants prey on sugarcane borers, Diatrea saccharalis (Fabricius). There, controlling fire ants increases the damage caused by the borers and the amount of pesticide that is needed.

Fire ants attacking caterpillars in field

Fire ants occasionally feed on germinating seeds and seedlings of corn, sorghum, peanut, soybean, watermelon, cucumber, sunflower and other field or cover crops, particularly in the spring when the weather is dry. They sometimes cause stand loss. Okra growers are constantly battling fire ants because they are attracted to the oils in the plant. Where soybeans are planted flat rather than on raised beds or rows, tall fire ant mounds along the rows interfere with harvesting equipment. During dry periods, the fire ants sometimes chew irrigation tubing, as in vegetable crops.

Fire ants feeding on sap

Fire ants feeding on corn

Fire ants tending aphids

Treatment Options

1	S-methoprene bait (Extinguish® ) is now registered for treating imported fire ants in cropland. Pyriproxyfen (Esteem) can be used by commercial growers in many tree fruits and nut orchards, as well as in certain vegetable and fruit crops. However, these baits are slow-acting and must be broadcast several months before maximum suppression is required. The most effective timing of application(s) and the economic benefits from control are still to be determined. Use where estimated losses exceed the cost of application, and monitor closely for secondary pest outbreaks in treated fields.
2	To prevent damage to corn and sorghum seedlings, treat the seed with a product registered for soil insect control, or band an insecticide such as Lorsban 15G (chlorpyrifos) over open furrows at planting where there is a history of stand loss. Gaucho® 480 Flowable (imidacloprid) is registered as a seed treatment for sorghum and many other crops.
3	Few contact insecticides are registered specifically for fire ant control in watermelon, sunflower and other crops, although some products containing pyrethrins (Pyrenone Crop Spray and others) are generally labeled for ant control in these sites. Insecticides registered for other pests on these crops (and known to be toxic to fire ants) are occasionally used to temporarily suppress foraging ants when damage is observed and the crop is threatened.