However, if we question why we are limited to just two applications the answer is not clearly defined. I think that part of the reason may be that it works so well on pests such as ants that a single application is all that is needed to knock out the local colonies of the ants and provide season-long control. 

A second reason may be that when the EPA originally approved registration of the product and its use it approved it conservatively. Manufacturers often get what they can to get the product onto the market, and then over time are able to add more and more uses. This was the case with Termidor, as a matter of fact, which began only as a termiticide but then added general pest uses as well. 

A third reason may be some nervousness and issues with the active ingredient fipronil. Over the years I have Googled this active and you can easily find a lot of negative dialogue about it. Now, we get negative attitudes about ANY pesticide, but the ability of fipronil to attach to insects such as ants and termites and paper wasps and to then be carried on that insect to its colony for further distribution can be worrisome. What if honeybees were exposed to the active ingredient? Could this easily wipe out the honeybee colony entirely. What if it gets onto other insects that are then eaten by beneficial insects? You can see where the concern may be, so limiting its uses to necessary ones on an appropriate time schedule seems to be okay. At least we have this weapon to fight some very difficult pests.

This also points out why our industry absolutely needs to adhere to the label and its limitations. I suspect there are plenty of licensed technicians using Termidor more often than allowed or on places away from the structure where it is not allowed, and this kind of misuse will lead to a product being taken away from us.