Insecticides and Application Techniques Used in Fire Ant Management
The use of the term "control" when dealing with fire ants seems
somewhat final, as if once something is done, the problem is solved. Control as defined by
the dictionary also seems to imply this concept -- consider (1) "to exercise
restraint or direction over; dominate; command," (2) "to eliminate or prevent
the flourishing or spread of." The term management may or may not fit the situation
any better; however, it seems to be somewhat less permanent and may imply something that
is ongoing. And when one is dealing with fire ants, the process is definitely ongoing.
Management may be accomplished by using baits, liquids (mound drenches),
powders/dusts or granules. The following materials and application methods are available
to the homeowner. Before starting your control program, read the entire page for
suggestions about the use of the products and application techniques.
Baits
Baits are a combination of the active ingredient plus a food material (for
fire ants, the food attractant is vegetable oil) that is attractive to the target pest, in
this case the fire ant. The ants are attracted to the oil in the bait, and it is picked up
and carried back to the mound. Here it is incorporated into the food chain and fed to the
queen and developing young. The following insecticides are available as baits and may be
used as broadcast applications or mound treatments.
Table 1. Baits and Amounts for Broadcast Application
| Bait |
Pounds/Acre |
Ounces/10,000 sq ft |
| Amdro (0.73% hydromethylon) |
1.5 |
5.5 |
| Award (1.0% fenoxycarb) |
1.5 |
5.5 |
| Distance (0.5% pyriproxyfen) |
1.5 |
5.5 |
| Extinguish (0.5% s-methoprene) |
1.5 |
5.5 |
Table 2. Baits and Amounts for Individual Mound Treatments
| Bait |
Tablespoons/Mound |
Comment |
| Amdro (0.73% hydromethylon) |
2 to 5 |
Do not place bait on
mound. Scatter it around the mound one to two feet out from the base of the mound. |
| Award (1.0% fenoxycarb) |
1 to 3 |
| Distance (0.5% pyriproxyfen) |
1 to 4 |
| Extinguish (0.5% s-methoprene) |
3 to 5 |
Baits-Method of Controlling. Amdro is a slow acting insecticide, and one can
expect to see results in one to two weeks. Award, Distance, and Extinguish are growth
regulators, and a decrease in ant numbers will not be noticeable for a minimum of six to
eight weeks. Even though it takes longer to get control with the growth regulators, the
control tends to last longer than with Amdro.
Application Sites. Baits listed above can be used in such areas as
lawns, picnic grounds, cemeteries, parks, school grounds, athletic fields, airports, etc.
They may also be used in and around container or field-grown ornamental and non-bearing
nursery stock and on sod farms. For a complete list of application sites, consult the
label of the product of choice.
Baits-Broadcast or Individual Mound Treatments. As with most
choices, there are pros and cons between these two application techniques. Consider the
following:
Broadcast
Application. What is a broadcast application? In this method a seeder or spreader is
used to scatter the bait in a uniform pattern over the infested site. The treater should
measure the length and width of the property in order to determine the amount of product
to use. The amount in table one is based on either an acre (43,560 sq ft) or 10,000 square
feet. A site measuring 100 feet by 100 feet gives 10,000 sq ft--one-fourth of this would
be 2,500 square feet or fifty feet by fifty feet. With most spreaders, the gate should be
set at its smallest opening, and the treater should walk back and forth across the area at
a fairly fast pace. Allow 6 to 8 feet between walking lanes.
- Broadcast Advantages. If the product is fairly evenly distributed across the property,
every foraging ant will have an opportunity to pick-up some of the bait. This eliminates
missed mounds.
- Broadcast Disadvantages. The treater must have an additional piece of equipment, and the
baits are fairly costly.
Individual Mound Treatment. This method of bait application may be used on small
areas with very few mounds. The bait is applied around the mound (not on the top of the
mound), usually one to two feet out from the base of the mound. Worker ants that forage
for food are more likely to find the bait when they enter or leave the mound when it is
used in this manner. For specific amounts see table 2.
- Individual Mound Treatment Advantages. One does not have to have a piece of equipment
for this type of application, and it tends to cost less than the broadcast method.
- Individual Mound Treatment Disadvantages. There is always the possibility of missing
mounds.
Mound Drenches
Materials (Table 3) used for mound drenches are formulated as liquids. A
specified amount is mixed with a gallon of water, and the solution is slowly poured into
the mound. It will generally take one gallon of solution to give adequate penetration into
the mound. A sprinkling can is a good container to use for this treatment. One of the most
common complaints that one hears about drenches is that "they don't work--the ants
only move from one area to the next." At any given time, ten to twenty percent of the
ants may be out foraging, and they will not reenter a treated mound. These
"displaced" ants will start a new mound (fire ants have a strong mound building
urge) somewhere in the vicinity of the treated mound; however, if the treatment was
successful, this "displacement" mound will not have a queen. Simply treat this
mound since the number of ants will be greatly reduced.
Table 3. Liquids for Mound Drenches
| Insecticide |
Tablespoons/Gallon |
| Diazinon (diazinon 22.4%) |
2 |
| Orthene (acephate 9.4%) |
2 |
These compounds are sold under a variety of trade names, and the percent concentrate
will vary with different trade names. Always check the percent concentration on the
purchased product to see if it is the same as the suggestions in table 3. If the
concentration is higher, the amount per gallon will be less than the one listed. The
reverse is also true if the concentration is less, the amount per gallon will be more than
the one listed.
Powders/Dusts
This method is convenient and works well as long as the mound is somewhat
moist and temperatures are moderate. During periods of drought, the mound covering dries
out and the powder or dust tends to remain on the mound surface. If this happens,
ultraviolet light will destroy the active ingredient. Hot dry weather also tends to push
the ants deeper in the mound, and this makes it harder to control the ants using
formulations of this type.
| Material |
Amount/Mound |
| Bengal Ultra Dust (deltamethrin 0.05%D) |
1 Tablespoon |
| Orthene (acephate 75% WP) |
2 Teaspoons |
Granules
This method is suited for individual mound treatments. For this method to
be effective, additional water may be needed, adding to the labor if this method is used.
| Insecticide |
Amount/Mound |
| Diazinon (diazinon 5% granules) |
½ cup |
Evenly distribute the specified amount over and around the mound, extending out about
one foot from the base of the mound. In most cases, one-half to one gallon of water
should be sprinkled over and around the mound to obtain the best results.
Recommended Treatment Program
Broadcast bait applications have been an accepted method of fire ant
control since the days of the USDA control programs. The following is based on these
programs, only the bait has changed.
I. Apply one to two bait applications four to five weeks apart:
- Baits work well during the spring and early summer.
- Some data suggests that the ants will pick up the bait after a rain; however, to be on
the safe side allow four to six hours of dry weather following the application.
- The more people who treat in a given area, the better. For example, if you are the only
person in your area treating, ants from untreated property will continue to infest your
property.
- Buy only the amount of bait that you will use during a given year. If the oil on the
bait becomes rancid, ants will not accept it.
II. As we move into the hot dry summer months, treat any mounds that appear with one of
the mound drench products.
III. (Optional). Apply an additional bait application in late September or early
October. This application should be one of the growth regulators.
Cost
What does it cost to treat for fire ants if the above program (including
the optional treatment) is followed? At $13.00 per pound and 10,000 square feet of treated
surface, the cost would be $4.47 per bait application. Three bait applications would cost
$13.41 per year, or if the optional treatment is excluded, the cost would be $8.94 per
year for bait applications. One to two dollars could be added for additional drench
applications if they are needed. These estimates are based on a "do-it-yourself"
treatment and does not include any charges for labor or equipment. Of course, if a
professional service is used, the costs will be higher.
Fire Ants and the Vegetable Garden
Fire ants can forage into the garden from surrounding areas, and they tend
to be more of a problem from the middle of the gardening season until harvest is complete.
Although, none of the baits are cleared for use in the garden, they can be used in turf
areas outside of the garden. Apply the bait in a band six to eight feet from the edge of
the garden soon after planting and apply an additional application in four to six weeks.
Since Amdro tends to work faster, this is the product that should be used under these
circumstances. If ants occur on the plants, treat the plants with any insecticide cleared
for use on the plant. Be sure to follow the days from last application until harvest on
the product of choice.
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