Termiticides (Part III)

The first installment (see "An Extensive Guide to the Different Classes of Termiticides (Part I)") of this two-part series discussed extensively about the first five classes of termiticides namely: (1) botanicals, (2) Chloronicotinyls, (3) Fluoroaliphatic Sulfonamides, (4) Inorganics and (5) Insect Growth Regulators. This time let us examine the remaining classes.

1. Microbials

There are two types of microbial termiticides; these are the Nematodes and the Pathogenic Fungi. Like Botanical termiticides, microbial termiticides are naturally occurring and are only artificially cultured when used as commercial termiticides. At present, Nematodes are never used as commercial termiticides because of its impracticality in terms of being artificially cultured as well as its effectiveness in field use. While Nematodes are proven to be effective in killing termites under controlled laboratory conditions, in the actual scenario, the possible harmful effects of Nematodes are easily ward off by termites.

However, Pathogenic Fungi have been found to be quite effective in termite control. In their natural habitat, termite colonies can be wiped out in weeks because of a pathogenic fungi outbreak. The fungus called Metarhizum anisoliae, a known natural termite killing pathogen is now being industrially produced by certain termiticide companies.

Pathogen fungi kill termites by germinating fungal spores that can penetrate inside their bodies. Once the spores get into their bodies, they begin to grow and compete with the microorganisms that live in the guts of termites. Fungal germination inside a termite's body is highly contagious that in a week's time, the entire colony can become fully infected by the fungus.

Quite interestingly, although termites are thought to be not capable of complex thinking, they have this unique ability to sense anything that might harm their colony. Any termite that exhibits weakening due to fungal infection is stunned by the soldier termites thereby reducing the rate at which the "disease" can spread. Overall, only about 10% of the entire population is bound to surely die while the remaining 90% faces a 50-50 chance of survival.

Pathogenic Fungi are used as termite bait, by being so; it does not kill termites immediately. It can be classified as an indirect termite repellent. Like all other baiting technologies, the use of pathogenic fungi takes more time before actual results are seen.

2. Organophosphates

Excluded in this list of termiticide classes are the Chlorinated Hydrocarbons which have been banned since 1988. Organophosphates follow the same fate, however, because the phasing out of all products belonging to this class is very recent (only by the start of 2006); I think that this class has to be discussed as well.

Termiticides under the Organophosphates class are not very harmful to the environment; however, these termiticides can greatly compromise human health. The recent findings of how these termiticides can cause blood and brain-related diseases made the Environmental Protection Agency or EPA imposed a permanent ban on all Organophosphates effective January of 2005.

The most commonly used Organophosphate is the Chlorpyrifos which is used as a chemical barrier. The chemical is used during preconstruction wherein gallons after gallons of Chlorpyrifos are poured directly into the soil on which the building will sit on. Chlorpyrifos is a direct termite repellent or it kills termites immediately upon contact. It was claimed by its manufacturers that the dead termites within the treatment zone will deter other termites from coming any close to the building being constructed.

3. Phenyl pyrazoles

Unlike other termiticides, Phenyl pyrazoles are really newly developed non-repellent termiticides. Released only in 2000, the only commercialized Phenyl pyrazole termiticide called Filpronil has been proven to be 100% effective in repelling termites and protecting a treated property from any termite attack. Field tests conducted in many areas in the United States gave Filpronil the good reputation that it now has.

4. Pyrroles

The only termiticide under the Pyrroles class that is currently being marketed is the Chlorfenapyr. Released in 2002, Chlorfenapyr has already earned for itself an undisputed fame in the field of termite control. Chlorfenapyr is also a non-repellent termiticide which acts slowly thus giving the termite time to go back to its colony and "infect" the other termites inside it. Chlorfenapyr works in two ways: (1) it can be ingested by the worker termites or (2) it can be carried by the termites' body.

Since termite workers are tasked to feed the other members of the termite colony, an infected worker termite will be a very good Chlorfenapyr agent. The ingested Chlorfenapyr will be mixed whatever it is that the termite worker feeds the larvae, the termite soldiers and the queen. The termite worker also dies afterwards because the Chlorfenapyr that it has ingested kills the microorganisms that break down the wood that it eats. Because of indigestion, the termite will die out of hunger.

Chlorfenapyr that is carried by termites' body is also effective in killing other termites. Once other termites come in contact with an infected termite, it too will carry the chemical and eventually die because of poisoning. Although the effect of the chemical is not abrupt, it can still kill termites very effectively.

5. Synthetic Pyrethroids

The inspiration behind Synthetic Pyrethroids is the chrysanthemum. The plant produces the extract called pyrethrum which has been found to be effective in repelling termites but is not easy to dispense because it easily breaks down even under normal temperature or pressure. Chemists are able to find a way to synthesize a laboratory chemical that is very similar to pyrethrum, but with more stability. Among these synthesized chemicals are the (1) Permethrin, (2) Fenvalerate and the (3) Deltamethrin. The chemical called piperonyl butoxide makes Synthetic Pyrethroids more stable than its natural counterpart.

Although Synthetic Pyrethroids do not kill termites in a massive scale, it is still considered as an effective termiticide because termites avoid places that are treated with it. However, careful handling is very necessary when using these types of termiticides because when they find their way into water surfaces, they can kill large numbers of fishes too.

6. Trifluoromethyl aminohydrazones

Hydramethylnon is the most common termiticide belonging to the Trifluoromethyl aminohydrazones class. It is also a termite bait system type, however unlike the other termite baits; it does not kill the microorganisms inside the termites' guts. Instead, it suppresses the termite's production of oxygen killing the termite through suffocation. Hydramethylnon is safe to use around humans and other warm-blooded animals because of its low toxicity level.

Once again, your favorite termite exterminator,
Michael Rozatoru :)