Having noted bed bugs have gained considerable resistance to common pyrethroids that exterminators used it is clear that legal applications will have less and less usefulness. If an exterminator, using old school methods, is to have any success at all it would necessitate either increasing the concentration of legal chemicals, using legal chemicals inappropriately, mixing chemicals inappropriately, or using illegal chemicals. In some ways I sympathize as these exterminators have been using chemicals as the primary tool for so long they don’t know what else to do. One exterminator stated to me directly “you want me to whistle at them”? Over the long term these uses should become apparent to the authorities and regulators as a record of all chemical sales are turned over to the authorities on a yearly basis.
A regulator might audit an exterminator and count the number of jobs done that use pyrethroids. A normal application would require x amount of chemical. If the exterminator bought 8x more chemical than required it would be a clue to using illegal concentrations of chemical. It would be hard to explain if an exterminator specializing in heat sterilizing homes for bed bugs used a lot of chemical. Or if someone purchased a lot of chemical for agricultural purposes such as “ Pounce” (illegal for residential structural work) but documented no agricultural customers it would be a clue. For someone willing to look illegal use is clearly visible in the paperwork.