There are differences in 'bug checking strategies' for different countries due to differences in bugs, pesticides, harvesting and packaging techniques (etc.). In Israel, I have recently encountered people who will not eat certain fruits or vegetables (strawberries, figs, cabbage, etc.) which they render 'uncheckable'. I was directed to the reputable kosharot website when trying to check a cabbage:
פוסקי הדור מציינים שבגלל כמה סיבות שונות אין לאדם רגיל (שאין לו הכשרה מיוחדת בבדיקת ירקות עלים) להשתמש בירקות עלים לא מפוקחים ומכונים בפי כל "ירקות גוש קטיף
The decisors of [halacha of this] generation mark that, for a number of different reasons, a regular person (who has no special preparation in checking leaf vegetables) is not to use leaf vegetables not supervised and nicknamed in everyone's speech "Gush Katif vegetables"
I found it strange that some vegetables are 'impossible' to be check for bugs, unless you are an expert. Certainly 'bug problems' now are no worse than the situations that our ancestors encountered. Why, nowadays, would some things be forbidden on the grounds that some bugs are impossible to be found/removed? Perhaps I am naive in thinking that all vegetables/fruits were eaten in the past as long as they were checked - perhaps they weren't, for this reason. If anyone can shed light on this it would be most appreciated.
(As an aside I went on a tiyul in Israel where our tour guide pointed out a hefker fig tree, picked a fig, opened it, spent time checking it and ate it. Another member of the tour said that his Rosh Yeshiva forbids eating figs because they cannot be checked. How is it possible that one of the shiv'at ha'minim are impossible to check and therefore inedible?!)