Can vegetables/fruit be uncheckable?

Question

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?!)

Answer 1

I actually had lunch with a mashgiach over Shabbos. I can't cite all of his sources, but we actually discussed this and he told me the following:

Because of environmental and health concerns, the pesticides we use are much more benign than those used as little as 25 years ago. We have infestations that would be simple to get rid of, but we don't.

Because of globalization, pests that used to only live in some countries are now all over the world, so there are many more pests that can occupy any given vegetable than there were in previous generations.

The Ohr HaChaim actually says that bug populations are inversely proportional with the spiritual state of the world, and "creepy crawly things" increase as our spiritual levels plummet. In a society which has allowed homosexual relationships, done away with laws of modesty, excuses (to put it nicely) abortion, and essentially allows adultery, it should be no surprise that bug infestations have increased.

As an aside, Chayei Adam in his explanation of the Yom Kippur viduy says that (in his time) the issur of eating bugs is almost unavoidable due to the difficulty of checking (see his entry for ashamnu).

Answer 2

I heard in the name of Rav Yisrael Belsky that in the past our bubbes and zeidies all has a tradition as to how to check the vast majority of fruits and vegetables the were in common use. With the advent of pesticides many people were of the opinion that the fruits and vegetables no longer needed to be checked, and the traditions of how to check were lost. When in the relatively recent past it has been discovered that many fruits and vegetables formally thought to be bug free are actually bug-ridden, such as cabbage, strawberries etc. there was no longer a common tradition as to how to check them, and we did not grow up with the awareness of the bugs that we need to look for. As a result there are those that say that these fruits and vegetables are no longer able to be checked by untrained eyes.

I can tell you from personal experience that checking a fig is extremely difficult. I was shown by someone who knows how to check them how similar the worms that infest them look to the seeds, and how without knowing what to look for it would be very easy to overlook them, thinking they are just another seed.