If you search for beaded fruit ornaments, you will see some that are made using push-pins, some that may be stitched, but I think most of them with very tiny beads are glued.

Nishedha's lemon appears to have some beads attached with pins (the largest ones) and I'd wager most others were glued on.

If I purchase some of these (they are mostly Christmas ornaments) I'll post about them in more detail.