I'm not above resorting to nasty chemicals IF I know for sure they'll be out of the picture as I'm spinning one up. I have Kontos, Avid , forbid and floramite but until I see a sign of pests those will handle I'll stick to less toxic non-systemics, And IF I choose to use those it will be very very early so there is little chance of residual. Preventative spraying is as easy as rosemary oil ( I prefer purespray green, nothing but petroleum oil), anything that suffocates is good as long as the device you use for spraying it covers well.