Broadcast Baits for Fire Ant Control

Imported Fire Ants, Ant Pests October 06, 2017 Print Friendly and PDF

cover picture for the broadcast baits publication. Broadcast Baits for Fire Ant Control with images of a hand-held bait spreader, an ant hill, and a Herd seeder mounted on a tractor.

 

When choosing a broadcast bait to control import­ed fire ants, hereafter referred to as fire ants, consumers and pest management professionals are faced with a confusing array of brand names and active ingredients with varying product performances. This guide addresses common con­cerns about broadcast baits to help consumers and professionals choose products that best fit their needs and situations.

Although the information presented here is as cur­rent as possible, frequent changes in technology, marketing and regulations affect the availability of and regulations for specific products. Therefore, this guide will focus on general principles of bait use, not specific products.

For specific, up-to-date information about avail­able of broadcast baits, visit The Latest Broadcast on Fire Ant Control Products.

Bait basics

A bait is a tool used to manage a pest population.  Baits contain an insecticide (preferably slow acting) combined with food that the target insect (or other pest) finds palatable if not attractive. In the case of ants, workers find the bait and carry it back to the colony, where it is fed to the larvae, work­ers and queens. Foraging workers may consume some of the liquid portion of the bait before returning the particle to the colony.

Most fire ant baits in current use are similar in appearance and odor and in their handling and application. These baits are small, oily, yellowish granules that smell like toasted corn. They consist of three main components:

  • Defatted corn cob granules serve as a means of distributing the attractant and the active ingredient. Although ants carry the granules to the mound, the granules have no insecticidal properties.  The foraging ants do not eat the granules since they cannot chew and swallow but feed the granules to the larvae who then digest the granules releasing the active ingredient to be passed to all in the colony.
  • Vegetable oil (often soybean) serves as both the attractant and active ingredient carrier. The active ingredient is dissolved in the oil. Preservatives and anti­oxidants are usually added to the oil to extend product shelf life.
  • The active ingredient is the actual insecticide that affects the ants.

Although active ingredients have different modes of action, they all serve to break the life cycle of the colony, resulting in its death. Baits containing insect growth regulators (IGRs) do not kill workers or queens. Instead, they disrupt larval development so that when the adult ants die of natural causes, they are not replaced, and the colony gradually dies out. Consequently, the speed of activ­ity of IGR baits depends on environmental conditions and may be very slow. Fast-acting baits (non-IGR baits) kill the queen and, to varying degrees, worker ants.

To learn more about principles of insecticide formulation and the mode of action of the various insecticides used in fire ant baits, refer to University of Georgia bulletin number 1412, Insecticide Basics for the Pest Management Professional, available on-line as a PDF at caes.uga.edu/publications.

Broadcasting vs. individual mound treatments

The single greatest advantage of broadcast baits over individual mound treatments (IMTs) is that you do not need to find the colonies to treat them.

It takes about an hour to thoroughly examine an acre of land for fire ants and mark the colonies for treat­ment and you have to assume you found all that need to be treated.  In reality hidden colonies escape detection, especially in hot, dry weather. With a broadcast bait, locating the colonies is unnecessary. All foraging ants from colonies that are visible and those that are not visible will have access to the bait.  Foraging ants from the smallest, most well-hidden colony to the largest, most obvious colony will likely pick up an effective dose of broadcast bait. The result is easy, thorough control over large areas.  

Broadcast baits have other advantages over contact insecticides and individual mound treatments:

  • In most cases, baits are the least expensive way to control fire ants.
  • Ants are controlled in an area for a longer period than with individual mound treatments.
  • Very little labor is required for the application.
  • Baits pose very little toxic threat to people, pets and wildlife.
  • There are very few environmental hazards as­sociated with baits.

Baits vs. granules

Many non-bait insecticides, including many that are used against fire ants, come in the form of granules. Some baits are actually labeled as “bait granules.” It is very important to know the differences between a bait and a contact insecticide granule and how to use each of them.

comparison images of an insecticide granule and a fire ant bait

Appearance and odor: Baits are yellowish, oily and have a toasted corn smell. Granular contact insecticides are usually gray or brown, not oily and have either a neutral or unpleasant chemical smell.

Application rate: Most baits are applied at broadcast rates from one to, at most, about 22 pounds per acre (an acre is 43,560 square feet, roughly the size of a football field or a square 209 feet on a side). Granular contact insecticides are applied at rates much higher than this, often on the order of 43 to 87 pounds per acre (1 to 2 pounds per thousand square feet).

Effect of moisture: Baits should never be watered in. Water ruins bait particles. Granular insecticides usually work faster and better when watered into the soil surface.

What does “broadcast-applied” mean?

Insecticides may be applied either directly to a target (mounds, in the case of fire ants) or to an entire area—a procedure known as broadcasting. Although baits may be applied either way with good results, they are best suited to broadcast application because of their ability to control most of the colonies in an area, regardless of the number of colonies, without the need to locate individual mounds.

How do you use baits successfully?

Many bait products are applied at a rate of 1 to 1½ pounds per acre of land. This is very little material and requires special application equipment. New “consumer” type baits are formulated as low concentrated high volume baits and are designed to be applied with common fertilizer spreaders with use rates up to 20 pounds per acre.

Regardless of the exact application rate, over-applica­tion offers little or no additional benefit in eliminating ants; it just costs more money.

Baits do require special conditions and handling for best results:

  • The ants must be actively foraging for bait.

Fire ants search for food (forage) at a wide range of temperatures and can be found foraging in al­most any season. However, they may be search­ing for only certain kinds of food, which might not be the oil of a bait. The only reliable way to confirm whether ants are feeding on bait is to offer them a small amount and see if they pick up the particles. Place a small amount of bait and wait about 30 minutes. If fire ants are actively foraging on the test bait it is a good time to broadcast fire ant bait.  Never apply bait during the extreme heat of the day, or in the morning when dew is present.

  • Use fresh bait.

The soybean oil in baits becomes rancid over time, making it unattractive to ants. Unfortunate­ly, bait product labels do not list a manufacture or expiration date. Rancid bait smells somewhat like old latex paint, unlike the fresh, toasted corn smell of fresh bait.

Because bait can spoil sitting on store shelves, it is important to check its freshness and return it to the seller if it is rancid.

  • Use the bait promptly.

Most companies claim that their products have a shelf life of 2 to 3 years if the packages remain unopened. Bait left open to the air may become rancid in a few months. Even when resealed and stored properly bait from an opened container should be used within a year.  Store baits in a cool, dry place without other chemicals.  Heat can make the oil in baits go rancid faster.  If other chemicals (gasoline, etc.) are stored with baits, the bait can absorb some of the odors, making the bait less attractive.

  • Do not allow baits to come into contact with water.

Water ruins baits. In favorable conditions, most bait is picked up overnight or even within a few hours, but for best results, do not apply a bait if rain is expected within 24 hours and do not ir­rigate the area for at least 24 hours. Avoid applica­tion when there is a heavy dew.

  • Do not mix baits with other insecticides.

To avoid contaminating bait with fertilizers or granular pesticides, wash the application equipment thoroughly.

What to expect from a bait treatment

Most broadcast baits work more slowly than do contact insecticides, though a few work just as fast. There is a trade-off, though: The faster a bait works, the sooner the area is open for reinvasion by new fire ant queens.

With any broadcast bait, you should expect 80 to 95 percent maximum control lasting 3 to 12 months, though the reinvasion rate depends on several factors such as weather and season. No product gives 100 percent control overnight or lasts forever.

Figure 1 shows results of a fire ant test applied in Texas in October 2004. These results are typical of what should be expected from the different types of broad­cast baits and other fire ant control products within the first few weeks.

Figure 2 shows data from the same test through 7 months. Note that some treatment areas are being reinvaded as oth­ers are maintaining or reaching full effectiveness.

Base your product choice on the time of the year that control is desired, the quickness of the reduction in activity and the duration of control that is needed.  Cost may play a role depending on the size of area that needs to be treated. No single product is right for every situation.

graph showing efficacy of various fire ant baits.  fast acting baits work more quickly but are subject to faster reinvasion by fire ant queens.  Baits containing insect growth regulators work more slowly but provide longer lasting control

Untreated (black): The number of mounds varies naturally by season and rainfall.

Advion Fire Ant Bait (yellow): This fastest acting of baits does most of its work within a week.Thereafter, the area is open for reinvasion.

Amdro Fire Ant Bait (red): This treatment represents fast-acting baits; it takes about 4 weeks to reach maximum control.

Insect Growth Regulator Bait (green): Most colonies do not die until warmer, drier weather the following year.

Talstar (blue): This treatment represents broadcast contact insecticides. Control is fast, and residual control can last for months.

TopChoice (purple): This is a contact insecticide that takes about a month to work fully. Residual control can be expected for a year. Reinvading colonies die in a few weeks.

Choosing a treatment method

For most situations, the best treatment is a bait. But despite their many good points, baits are not the best treatment for every situation.

For instance, a bait may cost $15 per acre when broad­cast. If there are 150 mounds in that acre, the per-mound cost is a mere 10 cents with little labor. But if there are only 10 mounds, the per-mound cost soars to $1.50 per mound. At 25 cents per mound, an individu­al mound treatment may be a better choice, except time would still need to be spent locating the mounds which may be better spent just broadcasting the bait.

Table 1 lists the characteristics of individual mound treat­ments and broadcast baits. Remember: These are gener­alizations; there is a range within each product category.

 

 

Table 1.  Advantages and disadvantages of individual mound treatments and broadcast baits.

Characteristic

Nonbait individual mound treatment (IMT)

Broadcast baits

Broadcast nonbait insecticide*

Speed of action

Fast (hours to a few days)

Varies (3 days to months)

Fast (hours to a few days)

Time to reinfestation

Not applicable, except where treated

2 up to 12 months

A few months; varies

Area retreatment times

Weekly to monthly

1 to 2 per year

1 to 3 per year

Need to locate mounds

Essential, takes about an hour per acre

Unnecessary

Unnecessary

Application labor

Moderate to high

Low

Low

Application equipment

Household items to professional equipment

$10 to $350 spreader

Fertilizer spreader (granules) Sprayer (liquid)

Cost per acre (43,560 ft2)

Depends on the number of mounds in the area

$10 to $18 (1.5 lb/acre rate)

$80+ (“consumer” product rate)

$50-$260 per acre; varies by product and rate

Cost per mound

1 cent to more than $1

Depends on the number of mounds in the area

Depends on the number of mounds in the area

Potential applicator toxicity

Low to high

Very low

Moderate to high

Potential environmental toxicity: leaching, runoff, etc.

Low to moderate

Very low

Moderate to high

Risk to nontarget ants

Low

Depends on the species; some other ants may benefit from fire ant removal.

High

Fire Ant Foraging Activity

Not required for application. Suitable for all season applications

Foraging activity required. Results vary during cool months even if foraging activity was observed.

Not required for application.    Suitable for all season applications

* This section refers to contact insecticides such as pyrethroids. Products containing fipronil work in about 4 weeks but have much lower potential applicator and environmental toxicity risks as well as lower risk to nontarget ants.

 

Applicator and Environmental Safety

When selecting and using baits, it is important to con­sider the safety of both the applicator and the environ­ment. Generally, broadcast baits use and introduce fewer toxic active ingredients into the environment than almost any other type of insecticide application resulting in reduced exposure to the applicator and other non-target animals.

The main environmental drawback of broadcast baits is that they may harm desirable ant species that pick up the bait. However, removal of fire ants from an area may be far more beneficial to the desirable ants than any ill effects caused by a bait.

Applicator safety

Although broadcast baits by almost any standard are less harmful to the environment and non-target organisms and are easy to apply, applicators should take a few safety precautions when applying them. Most precautions are designed to keep the bait granules from contacting your skin and eyes.

Pesticide handling precautions

  • Wear a long-sleeved shirt, untucked, and long pants left outside a boot.
  • Wear nonabsorbent gloves. Leather and cotton soak up oil and prolong exposure hazard.
  • Inexpensive aprons are good for keeping par­ticles out of pockets and oil off clothes.
  • Wear boots. Bait granules accumulate easily inside shoes.
  • Wear safety glasses or goggles. Particles are eas­ily blown by the wind and can get in your eyes.
  • If the bait contacts your skin, brush off the granules, then wash with soap and water. Remember: The ac­tive ingredient is in an oil, so soap is necessary.
  • Do not wear the clothes again before washing them separately from other laundry.

 

Application safety

  • The spinning rotor of an electric spreader can seriously injure your fingers. Before you approach the rotor, be sure that the spreader is turned off or, preferably, disconnected from the battery. Even the rotor of a hand-held spreader can cause a painful bruise or cut to a finger.
  • To prevent the particles from hitting others, do not allow anyone within 40 feet of an electric spreader.
  • Unlike with fertilizers or heavier granules, the wind greatly alters the distribution patterns and distances of bait, causing it to blow back onto the operator or into non-target areas. Adjust the swath spacing and safety buffers relative to the wind as you move back and forth over an area.

Environmental safety precautions

Take steps to minimize undesirable effects of broad­cast baits on the environment. Although the risks are slight, the precautions are easy to follow:

  • The label is the law.  Always follow label directions!
  • Never apply bait directly to water.
  • Do not apply bait to hard surfaces (paving, plas­tic, etc.) where water runs off quickly. Use a broom or leaf blower to blow bait granules and other insecticides onto grassy areas. NEVER let a granule remain on a hard surface where it might be washed into a local body of water.
  • Avoid application to non-target sites. For ex­ample, wooded and shady areas tend to harbor more desirable ants but fewer fire ants.
  • Do not apply bait to food-producing areas, such as vegetable gardens, orchards and pastures, unless the product is specifically labeled for use there.
  • Avoid using baits where poultry or other animals might easily pick up the bait particles. Remove the animals until the ants have gathered the bait (overnight is usually sufficient, or as directed on the label.)
  • If a high level of reduction in ant activity is not needed, consider using IMTs or no treatments where there are fewer than 20 colonies per acre.
  • Avoid over-application by using proper calibra­tion methods.

One pound per acre is a light scattering, not a yellow cloud!

Toxicity

Many people are concerned about pesticides in the environment. Table 2 outlines the characteristics of some representative baits and, for comparison, those of a few contact insecticides commonly used for indi­vidual mound treatments.

 

Table 2. Characteristics of commonly available fire ant baits and individual mound treatment chemicals.

Active ingredient

Brand name(s)

Concentration (as supplied)

Class or activity1

Active ingredient/ acre

Product Oral/dermal LD50 (mg/kg)2

Half-life in soil (days)

Broadcast Baits

 

 

 

@1.5 lb./acre

 

 

abamectin

Ascend, etc.

0.011%

IGR-like

0.00011 lb

>5,000/>5,000

21

fipronil

MaxForce FC

0.00045%

toxicant

0.000675 lb

>5000/>2000

128

hydramethylnon

Amdro, etc.

0.73%

toxicant

0.0073 lb

>5,000/>5,000

4

indoxacarb

Advion, etc.

0.045%

toxicant

0.00068 lb

>5,000/>5,000

43

metaflumizone

Siesta, etc.

0.063%

toxicant

0.00094 lb

>2,000/>2,000

198

methoprene

Extinguish

0.5%

IGR

0.005 lb

>34,000/>5,000

10

pyriproxyfen

Distance, etc.

0.5%

IGR

0.005 lb

>5,000/>2,000

8

spinosad

Come and Get It

0.015%

toxicant

0.00015 lb

>5,000/>5,000

14

Contact IMT

 

 

 

@150 mounds/ac

 

 

acephate

Orthene

50%

contact

        1-2 lb

>1,000/>10,000

3

bifenthrin, IMT

Ortho Max, etc.

0.2%

contact

0.06 lb

>5,000/>2,000

123

   Contact  broadcast                                                                                                                                                                        

bifenthrin, brdcst

Talstar

0.2%

contact

2 lb (high rate)

>5,000/>2,000

123

IMT = Individual mound treatment, brdcst = broadcast
1IGR = insect growth regulator; toxicant = slow insecticidal activity; contact = contact insecticide
2LD50 is the amount of labeled product in mg/kg body weight that will kill 50 percent of laboratory mammals (rats or rabbits) tested when administered either orally or dermally. Higher values indicate less-toxic pesticides.

 

Application Equipment

Broadcast baits are easy to apply. They require no mixing, little measuring or weighing, and one rapid pass over the area to be treated. They also require some specialized, relatively inexpensive application equipment to apply such small amounts.

The main reason to use such equipment is to avoid over-applying bait. Applying too much fire ant bait has little or no effect on product effectiveness, the envi­ronment, worker safety or any other factor. It does, however, increase the cost and is off-label.

If a little is good, a lot is not better. It’s just more expensive.

Over a large area, you must apply baits consistently and accurately for the treatments to be effective and economical.

Walk-behind lawn push spreaders and large PTO-powered fertilizer spreaders are not recommended for most fire ant bait applications.

The following are some of the more common types of effective bait application equipment. The list is not comprehensive, and the illustrations should be used only as examples. Any brand of spreader with the characteristics outlined here should broadcast bait effectively and accurately.

  image of a hand held fire ant bait spreader

 For small areas, not much larger than a typical yard

Type: Hand-held rotary (manual or battery powered) Cost: Less than $10 (manual); $20-$30 (battery powered)
Brand name: Numerous Availability: Feed, hardware, and garden stores
Bait distribution and rate accuracy: Fair to poor, in an 8- to 10-foot swath
Comments: These are inexpensive, rugged and good enough for around the home, but they cannot be calibrated accurately, and they usually overapply.  Because the stirring agitator works poorly, the spreader must be shaken to keep the bait flowing.
 hand cranked rotaty seeder used to spread fire ant bait

 For medium-sized areas (up to about 10 acres) or for high accuracy

Type: Hand-cranked rotary Cost: $25 to $30
Brand name: Earth-Way, etc. Availability: Lawn and garden centers
Bait distribution and rate accuracy: Excellent, in an 8- to 15-foot swath
Comments: Seeders can quickly pay for themselves by applying the proper amount of bait. The shaking gate agitator gives very good flow with few clogs. More area can be covered by having the applicator sit on the back of a vehicle.
 Herd GT 77 seeder used to spread fire ant bait

 For large areas (more than 10 acres) and frequent or heavy use

Type: 12V electric-powered

Cost: $400 to $550

Brand name: Herd Broadcast Seeder, model GT-77 (various mounts available) (see video) 

Availability: Farm or lawn equipment dealers, usually 2- to 3-day delivery
Bait distribution and rate accuracy: Excellent, in 20- to 30-foot swath
Comments: Can be mounted on anything with wheels and 12-volt power. 
  picture of the vicon pendulum spreader

 For large areas (more than 10 acres) and frequent or heavy use

Type: PTO driven Cost: $2,000-$3,000
Brand name: Vicon Pendulum spreader with clover attachment Availability: Search online
Bait distribution and rate accuracy: Excellent, in 20- to 30-foot swath
Comments: Can be mounted for use on tractor with PTO. Use of clover inserts aids calibration.
 fixed wing aircraft equipped with a bait spreader

 For very large areas, rough or wooded/brushy terrain

Type: Aerial application (see video) Cost: $2.50 to $4 per acre, application only
Brand name: Local certified aerial applicator
Bait distribution: Excellent and fast, but drift may be severe in crosswinds
Rate accuracy: Excellent, if calibrated and applied properly

Comments: Modifying aircraft to apply bait is simple and inexpensive. For details, see this aerial application guide.

 

Note: Never apply bait through a spreader without cleaning it first. Worker are extremely discriminatory about smells, and are capable of detecting fertilizer and herbicides that have been put through the spreader.

Spreader calibration

Why bother?

Baits applied at a typical rate of 1.5 pounds per acre are hard to see coming out of a spreader. Most people don’t believe that such a tiny amount will do anything. Even doubling the amount is barely no­ticeable—until you run out of bait. Over-application is always more costly than necessary. On the other hand, under-application or poor coverage with some products can result in poor fire ant control.

Because so many factors can change, it is best to calibrate your spreader before every application. Bait flow can be altered by temperature, humidity, bait brand and lot, even ground roughness and especially speed of applicator.  For large treat­ments, you must calibrate the day of the application because of the high costs involved.

Calibration by trial and error

How Much Bait Do I Apply?

[(Length x Width)/43,560] x [lbs./acre on bait label] = lbs. of bait to apply to target area

Trial-and-error calibration is easy for small areas and hand-held spreaders, but it is also recommended for large ground and aerial applications because it ac­counts for differences in bait flow caused by terrain and turbulence. You will need some type of accurate scale to calibrate. Kitchen, postal and fishing scales are inexpensive and easily available and do a good job.

Small areas and hand-held spreaders

Calculate the area to be treated, and weigh out the proper amount of bait following label directions. Set the spreader gate opening to about 3/16 inch and walk at a comfortably brisk pace. Be sure to keep the swaths even with as few overlaps or gaps as possible.

If you have bait remaining when finished, apply it in swaths perpendicular to the first, and open the gate slightly wider or walk faster the next time you apply. If you run out before finishing, add more bait and complete the job with a smaller gate opening. It is helpful to make note of the gate setting and walk­ing speed on the spreader with permanent marker to reference for your next application.

Large applications by vehicle or air

Mark a smaller area to treat for calibration (at least 1 acre for ground application). Weigh out enough bait into the hopper to cover the area plus enough to ensure that it does not “run dry” during application, and record the total amount. If using a Herd Broadcast Seeder, individual plates are available in the "Plate kit for Fire Ant Bait" to place in the bottom of the hopper to gauge the amount of bait that flows onto the spinner.  Each plate will be associated with specific ground speed and specific flow of the bait.  Please refer to the instructions for the Herd Broadcast Seeder Plate kit for Fire Ant Bait to make sure you choose the right plate for the rate of bait to be applied to the area.  An aerial applicator should have an estimate of a beginning gate setting.

Set the spreader at the height at which it will be used because this affects the swath width. Keep in mind that tall vegetation easily deflects bait particles.

Determine the swath width by spreading the bait for a few seconds and measuring the width of the pat­tern. It is also helpful to note how it changes or shifts to one side in the prevailing wind. You will need to compensate for this during application.

Apply the bait to the marked area at a maintainable, steady speed with even swaths. Ground infested with fire ants is often very rough, requiring slower speeds to maintain control of a vehicle.

After the application, remove all the bait from the hopper and reweigh it. Calculate the application rate based on the area you treated and the amount you used.

To increase the application rate:

  • Reduce the speed.
  • Reduce the swath width (lower the spreader)
  • Increase the gate opening.

To decrease the application rate:

  • Increase the speed.
  • Increase the swath width (raise the spreader).
  • Decrease the gate opening.

For minor corrections, begin by adjusting the speed, then the swath width.

Helpful Links for Spreader Calibration

Herd Seeder Calibration Tables for fire ant plates for various baits

Calibrating a Fire Ant Bait Spreader (Tennessee publication)

 

Choosing an application vehicle

Herd GT 77 seeder mounted on a tractor Tractors: The ability to set the throttle in a tractor makes for the most accurate application. Although a 3-point-hitch mount will need to be fabricated, the spreader can be mounted high enough to clear tall vegetation with no loss of vehicle stability (easily 3 to 5 feet). Connections to shut off bait flow or an electrical connection to stop the rotor are easy to make and operate by the driver.
Herd GT 77 seeder mounted on a pickup truck Pick-up trucks: Receiver mounting is fast and easy, but without mount modifica­tion, the spreader height is limited to only about 2 feet. It is also difficult to keep a consistent, slow driving speed. A mechanical shut-off is impractical for the driver to use, so an electrical switch must be installed to operate the spreader from the cab.
Herd GT 77 seeder mounted on an atv for spreading fire ant bait ATVs and utility vehicles: These work well for areas with sensitive turf, many ob­structions or rough terrain, but holding a steady speed on them can be tiring. The mounting height is limited to less than 4 feet to avoid stability problems. The driver can usually operate the spreader’s own mechanical shut-off or electrical switch eas­ily and with no modification.

 

Fine-tuning fire ant control with broadcast baits

When applied as directed, all bait products work. But there are several ways to make them work better, faster, longer and/or at a lower cost.

Application timing

Fast-acting baits kill not only the queens, but also worker ants that consume enough bait. The fast­est baits (fipronil, hydramethylnon, indoxacarb, metaflumizone, spinosad, and hydramethylnon + s-methoprene) work in 2 to 4 weeks. With the advent of baits containing indoxacarb or metaflumizone, the time has been reduced to about 3 days.

Slow-acting insect growth regulator baits (s-methoprene and pyriproxy­fen) depend on natural mortality factors—particu­larly old age, heat, drought and freezing cold—to kill the work­ers. Most slow-acting baits applied in the spring will eliminate colonies in 3 to 4 months. If applied in the fall, these same baits may not fully eliminate treated colonies until late spring the following year.

Bait combinations (hopper-blend treatments)

Research has shown that combining a fast-acting bait with a slow-acting bait as a hopper blend offers the best characteristics of both types of bait: fast action, thoroughness and forgiveness in coverage. The fire ant bait Extinguish Plus® is a blend of hydramethylnon + s-methoprene baits.  Be aware that in some states blending must be mentioned on the label in order for it to be legal.  Currently, the hopper blend combination of AmdroPro® (hydramethylnon) with Extinguish® (s-me­thoprene) or Esteem (pyriproxyfen) is on the labels for these bait products.   

The real benefit of the hopper blend is that you use one-half of each product and apply the mixture at the full rate of one. Therefore, you get the benefits of both at no extra cost.

Reduced rate and alternative method applications (skip-swath treatments)

Bait applications generally cost about $12 to $18 per acre per application. Although quite reasonable for home yards and high-value sites such as golf courses, this cost may be prohibitive for large ranches and wildlife management areas.

To reduce costs, baits can be applied at reduced rates and/or coverages, but the results are inconsis­tent. Generally, fast-acting baits should be applied at full rates and complete coverage. Slow-acting (IGR) baits can be applied at reduced rates and even in alternat­ing swaths (skip swath).

Tests have shown that products containing methoprene or pyriproxyfen can be applied in alternating 30-foot swaths with the spreader set to apply the normal 1½ pounds per acre. Results indicate that fire ant control is almost identical to full-rate, full-cover­age application, but half the material is used.

These applications are practical only on large, open areas, but they can result in major cost savings in both products and application. 

Products containing fipronil

Fipronil is one of the few active ingredients labeled for fire ant control both as a bait (MaxForce FC®) and as a granu­lar contact insecticide: TopChoice®, Taurus® G, Quali-Pro® Fipronil 0.0143G, and Taurus® Trio G.

The characteristics of the bait form of fipronil are like those of the other fast-acting baits.

There is a common misconception, even among pro­fessionals, that the fipronil granules are baits. These products are not baits. They are contact insecticide granules. However, their speed of control is much like a fast-acting bait—about a month, though Taurus® Trio G may also deliver a quick knockdown of fire ants especially foragers, due to added quick acting pyrethroids in formulation. Granular formulations are not consumed by ants. A granular formulation is one in which the insecticide, a contact insecticide, is coated onto a granule of clay or other material. Fertilizers, for instance, are often formulated as granulars. Following application, the contact insecticide must be released from the granule by allowing water to dissolve and disperse the clay, leaving behind a insecticide residual that kills insect when they come in contact with it. Watering in a granular formulation is necessary, but watering in a bait granule will ruin the bait.

Unlike fipronil baits, fipronil contact granules show true residual fire ant control for up to a year in many cases. Colonies moving into a treated area will contact the toxicant and die as if they had been treated. 

High-volume baits

In recent years, several products have emerged that allow homeowners to use common, push-type fertil­izer spreaders to apply fire ant bait. These products contain the same active ingredient as their parent product, but you apply much more actual bait for the same amount of active ingredient. These products may give more convenient and accurate applications for typical homeowners, but be aware that they cost considerably more than their parent products to treat the same amount of area. The effectiveness is similar.

Mixing bait with fertilizer

Buying a special spreader or mixing bait and fertil­izer to save a trip across the field are not suggested practices. However, recent field research and grower practice have shown good results if the bait and fertil­izer are mixed in the field and applied immediately. The longer a bait is in contact with fertilizer, the greater the chance of it not working because of salt contamination and unpalatability to the ants.

If you choose to mix bait and fertilizer, start with a small area and see if the bait works before risking the cost of a large treatment.

The latest news

Fire ant product availability and labeling commonly change several times each year. There is no practical way to keep such information current in a printed document, but there is a great need to keep it avail­able. The most up-to-date information on available fire ant bait products can be found in the publication The Latest Broadcast on Fire Ant Control.

Disclaimer

The products listed have been found to reduce the number of fire ant colonies compared to those in untreated plots in repli­cated scientific tests conducted by the Texas A&M AgriLife Extension Service and agencies in other states. Specific products are listed as a service to the reader. The lists of products here and on the companion Web site are not comprehensive. Neither eXtension, the Texas A&M AgriLife Extension Service, the Southern Region Integrated Pest Management Center nor other cooperating organizations endorse or discourage the use of any product mentioned. Product brand names are the registered trademarks of their respective companies.

 

 

 

 

 

 

Authors

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Texas A&M AgriLife Extension Service

Paul R. Nester, Extension Program Specialist, 

Robert T. Puckett, Assistant Professor and Extension Entomologist

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Auburn University and the Alabama Cooperative Extension System

Kathy Flanders, Extension Entomologist and Professor,

Kelly Palmer, Animal Sciences and Forages Regional Extension Agent

Fudd Graham, Research Fellow IV

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University of Georgia and the University of Georgia Cooperative Extension Service

Dan Suiter, Professor

Tim Davis, Ph.D.,  Chatham County Extenson Coordinator

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Karen Vail
Professor and Extension Urban Entomologist,
University of Tennessee Extension

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University of Arkansas System, Division of Agriculture, Cooperative Extension Service

John Hopkins, Associate Professor and Extension Entomologist

Kelly Loftin, Extension Entomologist

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Louisiana State University AgCenter

Dennis Ring, Entomologist, Extension Specialist, Professor

 

This content was originally published as E-268 by the Southern Region IPM Center. Funding for this publication was originally provided by the Southern Region IPM Center and Texas A&M AgriLife Extension Service.

 

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This work is supported by the USDA National Institute of Food and Agriculture, New Technologies for Ag Extension project.