Termites

Owing to their wood-eating habits, many termite species can do great damage to unprotected buildings and other wooden structures. Their habit of remaining concealed often results in their presence being undetected until the timbers are severely damaged and exhibit surface changes. Once termites have entered a building, they do not limit themselves to wood; they also damage paper, cloth, carpets, and other cellulosic materials. Particles taken from soft plastics, plaster, rubber, and sealants such as silicone rubber and acrylics are often employed in construction.

Humans have moved many wood-eating species between continents, but have also caused drastic population decline in others through habitat loss and pesticide application.

Termites are commonly viewed as pests in many countries, because of the damage they can cause to structures and similar nuisances. In April 2011, wood-eating termites were blamed for reportedly consuming more than $220,000 worth of Indian rupee notes.[15]

Precautions:

• Avoid contact of susceptible timber with the ground by using termite-resistant concrete, steel, or masonry foundations with appropriate barriers. Even so, termites are able to bridge these with shelter tubes, and it has been known for termites to chew through piping made of soft plastics and even some metals, such as lead, to exploit moisture. In general, new buildings should be constructed with embedded physical termite barriers so no easy means remain for termites to gain concealed entry. While barriers of poisoned soil, so-calledtermite pre-treatment, have been in general use since the 1970s, it is preferable that these be used only for existing buildings without effective physical barriers.
• The intent of termite barriers (whether physical, poisoned soil, or some of the new poisoned plastics) is to prevent the termites from gaining unseen access to structures. In most instances, termites attempting to enter a barriered building will be forced into the less favourable approach of building shelter tubes up the outside walls; thus, they can be clearly visible both to the building occupants and a range of predators.
• Timber treatment
• Use of timber that is naturally resistant to termites, such as Syncarpia glomulifera (turpentine tree), Tectona grandis (teak), Callitris glaucophylla (white cypress), or one of the sequoias. No tree species has every individual tree yielding only timbers that are immune to termite damage, so even with well-known termite-resistant timber types, pieces occasionally will be attacked.

When termites have already penetrated a building, the first action is usually to destroy the colony with insecticides before removing the termites' means of access and fixing the problems that encouraged them in the first place. Baits (feeder stations) with small quantities of disruptive insect hormones or other very slow-acting toxins have become the preferred, least-toxic management tool in most western countries. This has replaced the dusting of toxins direct into termite tunnels that had been widely done since the early 1930s (originating in Australia). The main dust toxicants have been the inorganic metallic poison arsenic trioxide, insect growth regulators (hormones such as triflumuron), and more recently fipronil, a phenyl-pyrazole. Blowing dusts into termite workings is a highly skilled process. All these slow-acting poisons can be distributed by the workers for hours or weeks before any symptoms occur and are capable of destroying the entire colony. 

More modern variations: chlorfluazuron, diflubenzuron, hexaflumuron, and novaflumuron as bait toxicants, and fipronil, imidacloprid, and chlorantraniprole as soil poisons. Soil poisons are the least-preferred method of control, as this requires large doses of toxin and results in uncontrollable release to the environment.

The termites' effects are damaging, costing the southwestern United States approximately $1.5 billion each year in wood structure damage. To better control the population of termites, researchers at the Agricultural Research Service have found a way to track the movement of the destructive pests. In 1990, researchers found a way to safely and reliably track termites using immunoglobulin G (IgG) marker proteins from rabbits or chickens. In field tests, termite bait was laced with the rabbit IgG and the termites were randomly exposed to feeding on this bait. Termites were later collected from the field and tested for the rabbit-IgG markers using a rabbit-IgG-specific assay. However, this method of testing for the tracking proteins is expensive. Recently, researchers have developed a new way of tracking the termites using egg white, cow milk, or soy milk proteins, which can be sprayed on the termites in the field. This new method is less expensive because the proteins can be traced using a protein-specific ELISA test. The ELISA test is more affordable, because it is designed for mass production. Researchers hope to use this method of tracking termites to find a more cost-effective way to control the damaging pests. [3]


Source: http://en.wikipedia.org/wiki/Termites#Timber_damage