I wouldnt be so worried about the bugs as I would the pesticides. When using live plants from a nursery or such, it is best to give the plant a 30-day "quarantine" period before adding it to your enclosure. First it is best to take the plants out of its current living arrangement and turn it upside down and rinse it in soapy water, rinse all soap off, replant it in new soil, then mist the plants leaves etc for the remainder of the 30 days. Even since you have rinsed all the surface pesticides off, it is still witihin the plant for some time after so it best to let it sit a while longer. Be sure to pick a healthy, clean-looking specimen to begin with and it should all be fine.