Except that H2O completely denatures or destroys the effectiveness of Diatomaceous Earth. So logically or theoretically DE works well in the Atacama Desert where no rainfall has ever been recorded or reported for at least the last 500 years. The trouble is that there also aren't any plants growing in the Atacama Desert to test DE on, so logically we are unable to know DE's true long term effectiveness in a truly dry ecosystem. I will tell you this, a half a jar full of DE with a heaping tablespoon full of Fire Ants added then shaken to combine equals a heaping tablespoon full of P!$$#& off Fire Ants, that is once the ants dig their way back to the surface.With logic like this, one might think it necessary to flood your home in order to wash your face. FYI, it is possible to dust the entire plant and then any bug that crawls on it or lands on it will come in contact with the DE...
Not only is it possible, but that is the only way that a logical person would do it.