Vegetables which are normally not infested

Hi,

Species of vegetables which are normally not infested with non-kosher bugs or worms do not require close checking for infestation.

Species of vegetables which are normally infested with non-kosher bugs or worms, but which undergo treatment during their growth to eliminate infestation, should be checked, if it is possible that the treatment was not done. Where it is very likely that the treatment was done, such as where the producers have a strong financial incentive to carry it out, then there is no need to check.

(Rav Moshe Feinstein, Igrot Moshe Yoreh Deah 2:25)

Have a great day,
Mordechai