Insects or pests do not attack healthy plants. This is the same for humans and animals too.
Just want to add some interesting facts. Weeds are involved in the same clean-up job as are the beneficial Bacteria within each of our Human Cells. These critters are made within ALL biological Cells to keep the Cell in prime condition to maintain Homeostasis. Because biological Life leaves a lot of spent residue in its everyday functioning, without the assistance of Bacteria, every creature on this planet would clog up in hours and cease functioning. Life on Earth cannot survive without Bacteria and cleaning up the mess!