Nothing can be further from the truth. Most (in fact all) pesticides used are designed to kill biological cells. So pesticides do not distinguish between a caterpillars cell or a humans. All pesticides are harmful to humans, some in tiny doses, some in large doses.
FYI - Landmark lawsuit claims Monsanto hid dangers of cancer caused by its weedkillers. https://www.theguardian.com/business/2018/may/22/monsanto-tr...