Small weapons of mass destruction
Formosan subterranean termites feed on wood (REUTERS)
Before getting rid of termites on your property, let’s be fair. The termites, after all, were the original inhabitants of the patch of earth you built on. Our long battle against them has been fraught with harm against not just them but the environment and ourselves.
The trouble with termites is they like wood and we tend to fill our homes with their favourite food. They have been around much longer than us, living in sophisticated hierarchical colonies as far back as a hundred million years ago, when we weren’t anywhere close to being even upright walking apes. The creatures we refer to as weyas or white ants are survivors, subterranean or soil-dwelling termites, a species more closely related to cockroaches than to ants. Like cockroaches, they enclose their eggs in cases, but display ant-like social behaviour.
The weya or subterranean termite belongs to the Rhinotermitidae family. One of hundreds of termite families, this group must maintain contact with soil in order to nest and is responsible for much of the structural damage to homes. Not all termite families damage homes, and in general termites play an important ecological role in decomposing organic matter. Those spotted in piles of wood in the garden may be dampwood termites, a cousin that won’t cause much damage to a home. An untreated home fitted with wood touching the ground is an attractive food source to subterranean termites.
“Subterranean termites don’t stray too far from their colony,” says Raja Mahendran, urban and agro pest control expert and consultant to global industries. “Homes are particularly inviting to them, containing materials that are softer to bite, easier to chew, like paper and cardboard materials.”
Pesticide ban
Chemical termite-control methods date to the early 1900s, when a variety of insect-killing substances became popular. Even as recently as the early 1980s, pest control organisations were using chlorinated hyrdrocarbons such as chlordane, an agro pesticide and relative of DDT, to free properties from termites. When building a house, the entire building site would be saturated with it, making it unlivable not just for termites, but other creatures like earthworms. Over time, however, chloradane’s carcinogenic properties and the damage it caused to the environment were discovered. Its use as a pesticide was banned in the 1980s.
Rachel Carson’s “Silent Spring” released in 1962, detailing the link between pesticides and the loss of certain wildlife species, including birds and fish at the end of the food chain, alerted the world to the need for a sea change in approach. That change took place very slowly however and it is only now that the industry is beginning to apply integrated methods of pest control, including termite management based on an understanding of the insect and its environment. The mass destruction method is giving way to a multi-focal approach using a variety of solutions that strategically minimise negative impacts on users and the environment.
Pre-construction termite proofing
Termite proofing a house takes place in two stages: pre-construction and post-construction, explains Mahendran. In the first, the house is made deadly for termites before it is built. The building site is anti-termited with a termiticide and then the house is built on it, so as to remain termite-free for some decades. The idea is to create a no-go zone for termites — a chemical barrier — between the house and the pests.
Organo-phosphate solutions, using chemicals that affect the nervous functions of insects, followed choladane. But although they appeared promising at first, it was found the chemicals broke down in alkaline environments like concrete, rendering them ineffective.
The solution was to build reticulation systems, networks that functioned like irrigation systems under and around the foundation at the time of construction, allowing treatments to be repeated every three to five years to keep the property termite-free indefinitely, says Mahendran. However, this group of pesticides was found to also affect the nervous systems of humans exposed to it over long periods.
Building walls to keep them out
Nowadays, the industry is moving towards physical measures, for example keeping termites out with meshing and netting treated with termiticide, he says. These create a barrier between the house and them. Although studies have indicated these solutions are relatively safe for humans, it is wise to consider the possibility that they too may be disproved over time.
New earth-friendly solutions, like making buildings termite proof, are arising. For example, incorporating plastic sheeting impregnated with termiticide into the foundation, allowing termites to live beneath and away from the house for thirty to forty years. Newer measures include anti-termite stainless steel meshing, which works like a mosquito net. There is also a termite-proof cementitious parge, ten or twenty times stronger than concrete, used to seal crevices, especially in L-shaped parts of the foundation slab.
Post-construction solutions
What happens if a house is past its termite proof prime or has not been termite proofed at all. You have to create that barrier, which is difficult to do in a built house, says Mahendran. The industry solution is to drill holes about every half a metre on the floor along the walls, and inject in chemicals to saturate the soil underneath between the two points. Usually, the pest control agent will drill every half a metre and fill the hole with chemicals, creating a continuous barrier against termites underground.
Subterranean termites are very intelligent and persistent, warns Mahendran. A termite’s mud tube is waterproof, very strong and hard to penetrate. There are termites who tunnel through the chemicals and die so that the colony can live.
The worker termites cause the damage, setting up a perimone trail for others to follow, gathering food to feed their queen, a huge thing whose job it is to lay eggs. The eggs become workers or soldiers who guard the entrance of the colony. Worker termites are very loyal, which is why some even turn suicidal in their efforts to support the group. The industry calls those who die for the cause “kamikaze termites”. Little by little they demolish the toxic barriers we establish, creating a hard safe tube around them as they attempt to get into the house. They die in the process, but cut a path into a home for their colony.
Modern biological warfare
Modern treatments based on an understanding of the insect and its behaviour have devised solutions that attract or bait termites and create conditions to eliminate entire communities while causing minimal damage to the environment and home. These are usually strategically positioned in the ground around and under the house eliminating the necessity to drill holes in the floor.
These methods could be considered biological warfare. Some confuse the insects when consumed, leaving them disoriented and unable to return to the colony. Others use woods for example that naturally cause fungal infections in termite colonies, and thus create an epidemic at the source. Then there are growth regulators that affect growth cycles, causing termites to remain at baby stage indefinitely. All result in the eventual death of the colony.
Like most pest control methods, treatments are continuous. Pest controllers monitor sites regularly for signs of termite activity. In the past, they would visit homes to do site checks by manually searching for signs of infestation themselves. Today they are more likely to use electronic equipment containing radar that detects termites, or the Red Eye, a contraption that is planted around the premises as a preventive treatment to detect termite activity.
“Termites are a crucial link in the earth’s cycle of life. However, killing a colony near your house is not going to cause a big problem to the eco-system. Even if you eliminate the colony, another may start in a couple of years. The treatment doesn’t prevent it; it simply kills the colony. But it’s still more environmentally sound because it is more focussed, and there is no contamination of the soil, and no killing of non-termites. Today, termite control is more effective and very specific to termites,” Mahendran says.
If you are considering termite proofing your home, ask your pest control agent about all the available options and be sure you understand the residual effects of treatments.