The Untouched Apple
This is something you rarely see--an Esopus Spitzenburg Apple, unblemished, free of nibbles and insect holes, pristine as a hot house specimen. This ancient New York apple tastes wonderful--to heirloom apple fanciers, to varmints, to insects, and even to pathogens. It is reckoned so "vulnerable" that many now refuse to grow the apple because it "invites pestilence." But I think this is the very apple we should be seeking out.
I have always thought that the quest to produce a plant that insects or animals won't eat in order to ramp up productivity was one of the more perverse ambitions of contemporary plant breeding. It was precisely the avidity with which birds, bugs, and beast fed on certain wild plants that made humans seek them out for domestication.
Justus Leibig showed in the early 19th century that all life is dependent on the recirculation of certain chemicals, from air, to soil, to plant, to animal. The nutrient cycle is operable. That other things are ingesting something is a strong recommendation it may be good for you. [It isn't an absolute assurance of course--I've seen many a turkey buzzard gobbling carrion along southern highways to know that critter has a more robust gastic system than I.] So as a general rule I don't want to chew on anything a bird or bug refuses to touch. And those things like the Esopus Spitzenberg that everything wants to munch, well those are precisely what I want. And if you are growing the things--get netting.