Termite control insecticides have long been judged according to these two traits: repellency and toxicity (which is sometimes alternatively called “lethality”, appropriately enough). The insecticides are measured for their ratings in both aspects, in order to determine how useful they are and what sort of application is most recommended for them. Various insecticides, after all, have been shown to be either more or less effective in certain applications and soils as well as in fighting specific kinds of termites.
Of late, however, there has been a gradual shift in emphasis regarding the ideal ratings of termite control substances in these two traits. Instead of high-repellence chemicals, chemicals with low repellence statistics are now being preferred. Furthermore, toxicity mechanisms are changing, with scientists and termite treatment developers and inventors recommending substances with what is called delayed toxicity.
Delayed toxicity in a substance means exactly what its name suggests: the lethal or poisonous aspect of the chemical does not take action upon immediate contact, but rather later on, following infection or contagion of an organism, as it were. The beauty of the delayed toxicity chemical is patent if you know how termites work. If soil in a passage has been impregnated with an instant toxicity substance, termites coming into contact with the soil would be likely to die almost upon contact and stack up there, blocking the passage. While other termites might in some cases try to clear out the blockage, it is far more likely for them to avoid it altogether, partly because they would learn to isolate the area where so many of their kind have clearly perished from some malign influence.
With a delayed toxicity substance, however, infected termites are able still to function normally for quite a while following contact, and may even go back to the colony. Since termites have a habit of grooming each other, the spread of the toxin would be very fast after that. This is why many termite treatment specialists are now opting for delayed toxicity chemicals in order to better the rates of infection for the poison.
Anti-termite chemicals that rank high in repellence are best considered termite prevention substances instead of termite control ones, scientists explain, and termite control experts agree. After all, there is a significant difference between applying an insecticide with the intention of killing an infestation that has already taken root in your home and applying it with the intent of preventing such infestations from happening. With a termite prevention chemical, you need high repellence because you want to prevent the termites from even crossing the boundary. But if the termites have already passed that line of defense, the solution has already moved to elimination, not mere prevention.
