Besides the issue of trumois u'maisrois, the issue of infestation is very serious.
Some of the Israeli Hashgochas write on the package that it must be washed, which most Americans see a kosher emblem they (become illiterate) just open and consume.
The Aida charaidus Yerushalem has a new emblem that states clearly the vegetables must be washed prior to consuming, etc.
The fruits and vegetables with the Hashgocha of Rav Efrati may contain insects that will not come off in washing. Also any frozen fruits or vegies with his hashgocha should not be consumed at this time.