My understanding of this, and this is also something that is enforced at certain us state borders as well, is this is primarily about insect and other parasites

My understanding of this, and this is also something that is enforced at certain us state borders as well, is this is primarily about insect and other parasites that may be on/in the fruit (or their eggs). I remember having to toss a bunch of fruit at the california border a few years back.