Insecticides for Termite Control

Dennis Ring, Wilson, Gary K.  |  8/9/2010 7:27:32 PM

Termites cause more damage to homes than all other natural disasters combined, $1.7 billion annually. Infestations can go undetected for years, hidden behind drywall, brick veneer, paneling, carpets, vinyl floor coverings and other obstructions. Termites can feed on exposed wood and still not be detected, because they leave the outer surface intact. Subterranean termites usually nest in the ground, and tunnel through the soil in search of food and water. They penetrate houses through crevices as small as 1/32 of an inch and gain entrance through the hollow bricks and blocks, expansion joints, wooden supports, cracks in concrete slabs and plumbing and utility passages.

Modern houses make extensive use of concrete slabs, and for the most effective termite proofing much of the chemical barrier needs to be put under these slabs. Termidicides (chemicals used to kill termites) are used as a chemical barrier around and beneath structures to block all possible routes of termite entry. It is easier to apply a barrier treatment before a slab has been poured. Once the house is built, there are many obstacles to a complete barrier treatment. Walls, floor coverings, paneling and other obstructions hide many possible entry points. Specialized equipment such as drills, hollow rods and high pressure sprayers are needed to inject hundreds of gallons of chemical underneath and around your house. After the slab is poured or the house built, this is a very difficult “do it yourself project.”

Termidicides can be classified into two groups, repellants and non-repellants. The repellants create a physical barrier that termites will not cross, or if they do become exposed for a significant length of time, will cause the death of the termite. These compounds have controlled termites effectively for years. Some repellants have provided over 12 years of control at certain sites. Generally repellant termidicides are lower in cost than non-repellants.

Non-repellant termidicides allow termites to travel through treated areas, rather than excluding them. The termites die after they are exposed to the insecticide. The new non-repellant termidicides are more expensive but also more effective.

Termite bait systems are a relatively new technology that target the termites rather than attempting to protect a structure. Most bait products are inserted into the ground around the periphery of the structure. Untreated wood may be used to monitor termite activity. Once termites appear in the wooded monitors; toxic baits replace the untreated wood in the monitoring stations. The foraging termite workers consume food themselves then later regurgitate part of it into the mouths of other colony members. Thus, once workers have fed on the treated baits, they disperse the toxicant throughout the colony. Non-repellant termidicides are also passed among colony members in this manner. Baits are environmentally friendly due to extremely low toxicity to humans and pets, but monthly monitoring makes it one of the more expensive control programs. Since the structure is not directly protected, it is at risk. This drawback may be overcome by using baits in combination with a barrier treatment.

For LDAF Approved Termidicides click here.

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