In the control of red imported fire ant infestations, there are
primarily two types of weapons: bait formulated insecticides and contact
insecticides. These products work differently and it is important to
understand these differences in order to get the most benefit for the
dollar spent.

	A bait formulated insecticide combines an ant-attractive food
source with an insecticide. These products are only effective for
controlling fire ants when the ants feed on the bait and ingest the
insecticide. Because ingestion is required for them to work, they are
more specific for targeting ants. 

	There are two general ways in which bait products work: 1)
direct toxicant, and 2) insect growth regulators or IGR's. Direct
toxicants poison all stages of ants, including adults, while insect
growth regulators cause the queen to lay infertile eggs or prevents the
ant larvae from developing into worker ants. Insect growth regulators
are slower acting than toxicants. Both types of bait products are slower
to kill ant colonies than contact insecticides. Because of the slower
rate of action, re-invasion by fire ants is considerably slower than
with contact insecticides.

	Bait formulations are best applied as a broadcast because the
bait allows ants from all colonies in the treated area to collect the
bait, rather than trying to locate individual mounds. Also, bait
insecticides not collected by the ants rapidly decompose in the
environment. It is best to treat late in the afternoon when you don’t
expect rain for 12-24 hours. Available baits include: Amdro, Award or
Logic, Ascend, Extinguish, Justice, Spectracide Fire Ant Bait and
Eliminator Fire Ant Bait.

	Contact insecticides are formulated to kill insects upon
contact, so you must get the insecticide to the ants instead of them
coming to get the bait. These products come in different forms,
including granules, dust, powder, and liquid. Some of the more common
insecticides include: Orthene, Talstar, Rapid Kill, Organic Solutions,
Citrex Fire Ant Killer, Over N Out, Ortho Fire Ant Killer, Once n’
Done and others.

	Most contact insecticides should be placed on top of the mound
to insure that it comes in "contact" with as many ants as possible.
Dusts sift through the top of the mound and the ants that walk through
the dust will carry it on their bodies inside the colony. Granules must
be watered into the mound when directed by label so that the toxic
ingredient is washed into the nest to contact the ants. If not applied
properly the ant colony will just move to a new nesting site. Over N Out
or Top Choice is a little bit different type of contact insecticide.  It
is a slow-acting contact insecticide with long persistence in the
environment achieving maximum control in about 3 to 6 weeks. It should
be broadcast over the entire landscape. Control lasts for about a year.
Some colonies may move into the treated areas but only persist for a
short time, before the product  eliminates the ants.

	Another tip for using contact insecticides is not to disturb the
mound when applying individual mound treatments. When the mound is
disturbed the queen(s) is moved to another location.  Since only the
ants coming in contact with the treatment are killed, the treatment will
be less likely to kill the queen and thus the colony. When the label
instructions are not followed, the treatment may not kill the fire ant
colony or, may cause the colony to split into more colonies.

	 There are now a number of “organic” alternatives for fire
ant control around the home and garden. Spinosad is considered organic
because it is produced from a bacterial fermentation process that
produces a toxin, which is extracted and put into bait at very low
concentrations. It works by disrupting the ant's nervous system. The
spinosad baits (Justice, Eliminator Fire Ant Bait, Strike, Maxide, or
Penn-Kill Fire Ant Killer) works well in small areas, or as an
individual mound treatment. Abamectin baits (PT 370 Ascend Fire Ant
Stopper Bait and Raid Fire Ant Killer), control fire ants and related
ants. It is a natural fermentation product produced by a soil
microorganism, Streptomycetes avermitilis, an actinomycete.  There is
also a contact dust containing pyrethrin and diatomaceous earth (Organic
Solutions- Multipurpose Fire Ant Killer) that can be used as an
individual mound treatment.

	As you can see there are loads of choices available to use for
battling fire ants around the home and garden. Although some are better
than others, all have been proven to help reduce fire ant problems.

Don’t forget to send your garden questions to Plant Answers at
9020 FM 1484, Conroe TX 77303 or e-mail me at t-leroy@tamu.edu .
Educational programs of Texas Cooperative Extension are open to
all citizens without regard to race, color, sex, disability, age or
national origin.